nsz Git - cparser/blob - parser.c

   1 /*
   2  * This file is part of cparser.
   3  * Copyright (C) 2007-2008 Matthias Braun <matze@braunis.de>
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  18  * 02111-1307, USA.
  19  */
  20 #include <config.h>
  21
  22 #include <assert.h>
  23 #include <stdarg.h>
  24 #include <stdbool.h>
  25
  26 #include "parser.h"
  27 #include "diagnostic.h"
  28 #include "format_check.h"
  29 #include "lexer.h"
  30 #include "symbol_t.h"
  31 #include "token_t.h"
  32 #include "types.h"
  33 #include "type_t.h"
  34 #include "type_hash.h"
  35 #include "ast_t.h"
  36 #include "entity_t.h"
  37 #include "lang_features.h"
  38 #include "walk_statements.h"
  39 #include "warning.h"
  40 #include "adt/bitfiddle.h"
  41 #include "adt/error.h"
  42 #include "adt/array.h"
  43
  44 //#define PRINT_TOKENS
  45 #define MAX_LOOKAHEAD 2
  46
  47 typedef struct {
  48         entity_t           *old_entity;
  49         symbol_t           *symbol;
  50         entity_namespace_t  namespc;
  51 } stack_entry_t;
  52
  53 typedef struct argument_list_t argument_list_t;
  54 struct argument_list_t {
  55         long              argument;
  56         argument_list_t  *next;
  57 };
  58
  59 typedef struct gnu_attribute_t gnu_attribute_t;
  60 struct gnu_attribute_t {
  61         gnu_attribute_kind_t kind;           /**< The kind of the GNU attribute. */
  62         gnu_attribute_t     *next;
  63         bool                 invalid;        /**< Set if this attribute had argument errors, */
  64         bool                 have_arguments; /**< True, if this attribute has arguments. */
  65         union {
  66                 size_t              value;
  67                 string_t            string;
  68                 atomic_type_kind_t  akind;
  69                 long                argument;  /**< Single argument. */
  70                 argument_list_t    *arguments; /**< List of argument expressions. */
  71         } u;
  72 };
  73
  74 typedef struct declaration_specifiers_t  declaration_specifiers_t;
  75 struct declaration_specifiers_t {
  76         source_position_t  source_position;
  77         storage_class_t    storage_class;
  78         unsigned char      alignment;         /**< Alignment, 0 if not set. */
  79         bool               is_inline : 1;
  80         bool               deprecated : 1;
  81         decl_modifiers_t   modifiers;         /**< declaration modifiers */
  82         gnu_attribute_t   *gnu_attributes;    /**< list of GNU attributes */
  83         const char        *deprecated_string; /**< can be set if declaration was marked deprecated. */
  84         symbol_t          *get_property_sym;  /**< the name of the get property if set. */
  85         symbol_t          *put_property_sym;  /**< the name of the put property if set. */
  86         type_t            *type;
  87         variable_t        *based_variable;    /**< Microsoft __based variable. */
  88 };
  89
  90 /**
  91  * An environment for parsing initializers (and compound literals).
  92  */
  93 typedef struct parse_initializer_env_t {
  94         type_t     *type;   /**< the type of the initializer. In case of an
  95                                  array type with unspecified size this gets
  96                                  adjusted to the actual size. */
  97         entity_t   *entity; /**< the variable that is initialized if any */
  98         bool        must_be_constant;
  99 } parse_initializer_env_t;
 100
 101 typedef entity_t* (*parsed_declaration_func) (entity_t *declaration, bool is_definition);
 102
 103 /** The current token. */
 104 static token_t              token;
 105 /** The lookahead ring-buffer. */
 106 static token_t              lookahead_buffer[MAX_LOOKAHEAD];
 107 /** Position of the next token in the lookahead buffer. */
 108 static int                  lookahead_bufpos;
 109 static stack_entry_t       *environment_stack = NULL;
 110 static stack_entry_t       *label_stack       = NULL;
 111 static scope_t             *file_scope        = NULL;
 112 static scope_t             *current_scope     = NULL;
 113 /** Point to the current function declaration if inside a function. */
 114 static function_t          *current_function  = NULL;
 115 static entity_t            *current_init_decl = NULL;
 116 static switch_statement_t  *current_switch    = NULL;
 117 static statement_t         *current_loop      = NULL;
 118 static statement_t         *current_parent    = NULL;
 119 static ms_try_statement_t  *current_try       = NULL;
 120 static linkage_kind_t       current_linkage   = LINKAGE_INVALID;
 121 static goto_statement_t    *goto_first        = NULL;
 122 static goto_statement_t   **goto_anchor       = NULL;
 123 static label_statement_t   *label_first       = NULL;
 124 static label_statement_t  **label_anchor      = NULL;
 125 /** current translation unit. */
 126 static translation_unit_t  *unit              = NULL;
 127 /** true if we are in a type property context (evaluation only for type. */
 128 static bool                 in_type_prop      = false;
 129 /** true in we are in a __extension__ context. */
 130 static bool                 in_gcc_extension  = false;
 131 static struct obstack       temp_obst;
 132 static entity_t            *anonymous_entity;
 133
 134
 135 #define PUSH_PARENT(stmt)                          \
 136         statement_t *const prev_parent = current_parent; \
 137         ((void)(current_parent = (stmt)))
 138 #define POP_PARENT ((void)(current_parent = prev_parent))
 139
 140 /** special symbol used for anonymous entities. */
 141 static const symbol_t *sym_anonymous = NULL;
 142
 143 /* symbols for Microsoft extended-decl-modifier */
 144 static const symbol_t *sym_align      = NULL;
 145 static const symbol_t *sym_allocate   = NULL;
 146 static const symbol_t *sym_dllimport  = NULL;
 147 static const symbol_t *sym_dllexport  = NULL;
 148 static const symbol_t *sym_naked      = NULL;
 149 static const symbol_t *sym_noinline   = NULL;
 150 static const symbol_t *sym_noreturn   = NULL;
 151 static const symbol_t *sym_nothrow    = NULL;
 152 static const symbol_t *sym_novtable   = NULL;
 153 static const symbol_t *sym_property   = NULL;
 154 static const symbol_t *sym_get        = NULL;
 155 static const symbol_t *sym_put        = NULL;
 156 static const symbol_t *sym_selectany  = NULL;
 157 static const symbol_t *sym_thread     = NULL;
 158 static const symbol_t *sym_uuid       = NULL;
 159 static const symbol_t *sym_deprecated = NULL;
 160 static const symbol_t *sym_restrict   = NULL;
 161 static const symbol_t *sym_noalias    = NULL;
 162
 163 /** The token anchor set */
 164 static unsigned char token_anchor_set[T_LAST_TOKEN];
 165
 166 /** The current source position. */
 167 #define HERE (&token.source_position)
 168
 169 /** true if we are in GCC mode. */
 170 #define GNU_MODE ((c_mode & _GNUC) || in_gcc_extension)
 171
 172 static type_t *type_valist;
 173
 174 static statement_t *parse_compound_statement(bool inside_expression_statement);
 175 static statement_t *parse_statement(void);
 176
 177 static expression_t *parse_sub_expression(precedence_t);
 178 static expression_t *parse_expression(void);
 179 static type_t       *parse_typename(void);
 180 static void          parse_externals(void);
 181 static void          parse_external(void);
 182
 183 static void parse_compound_type_entries(compound_t *compound_declaration);
 184 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
 185                                   bool may_be_abstract,
 186                                   bool create_compound_member);
 187 static entity_t *record_entity(entity_t *entity, bool is_definition);
 188
 189 static void semantic_comparison(binary_expression_t *expression);
 190
 191 #define STORAGE_CLASSES     \
 192         case T_typedef:         \
 193         case T_extern:          \
 194         case T_static:          \
 195         case T_auto:            \
 196         case T_register:        \
 197         case T___thread:
 198
 199 #define STORAGE_CLASSES_NO_EXTERN \
 200         case T_typedef:         \
 201         case T_static:          \
 202         case T_auto:            \
 203         case T_register:        \
 204         case T___thread:
 205
 206 #define TYPE_QUALIFIERS     \
 207         case T_const:           \
 208         case T_restrict:        \
 209         case T_volatile:        \
 210         case T_inline:          \
 211         case T__forceinline:    \
 212         case T___attribute__:
 213
 214 #define COMPLEX_SPECIFIERS  \
 215         case T__Complex:
 216 #define IMAGINARY_SPECIFIERS \
 217         case T__Imaginary:
 218
 219 #define TYPE_SPECIFIERS       \
 220         case T__Bool:             \
 221         case T___builtin_va_list: \
 222         case T___typeof__:        \
 223         case T__declspec:         \
 224         case T_bool:              \
 225         case T_char:              \
 226         case T_double:            \
 227         case T_enum:              \
 228         case T_float:             \
 229         case T_int:               \
 230         case T_long:              \
 231         case T_short:             \
 232         case T_signed:            \
 233         case T_struct:            \
 234         case T_union:             \
 235         case T_unsigned:          \
 236         case T_void:              \
 237         COMPLEX_SPECIFIERS        \
 238         IMAGINARY_SPECIFIERS
 239
 240 #define DECLARATION_START   \
 241         STORAGE_CLASSES         \
 242         TYPE_QUALIFIERS         \
 243         TYPE_SPECIFIERS
 244
 245 #define DECLARATION_START_NO_EXTERN \
 246         STORAGE_CLASSES_NO_EXTERN       \
 247         TYPE_QUALIFIERS                 \
 248         TYPE_SPECIFIERS
 249
 250 #define TYPENAME_START      \
 251         TYPE_QUALIFIERS         \
 252         TYPE_SPECIFIERS
 253
 254 #define EXPRESSION_START           \
 255         case '!':                        \
 256         case '&':                        \
 257         case '(':                        \
 258         case '*':                        \
 259         case '+':                        \
 260         case '-':                        \
 261         case '~':                        \
 262         case T_ANDAND:                   \
 263         case T_CHARACTER_CONSTANT:       \
 264         case T_FLOATINGPOINT:            \
 265         case T_INTEGER:                  \
 266         case T_MINUSMINUS:               \
 267         case T_PLUSPLUS:                 \
 268         case T_STRING_LITERAL:           \
 269         case T_WIDE_CHARACTER_CONSTANT:  \
 270         case T_WIDE_STRING_LITERAL:      \
 271         case T___FUNCDNAME__:            \
 272         case T___FUNCSIG__:              \
 273         case T___FUNCTION__:             \
 274         case T___PRETTY_FUNCTION__:      \
 275         case T___alignof__:              \
 276         case T___builtin_alloca:         \
 277         case T___builtin_classify_type:  \
 278         case T___builtin_constant_p:     \
 279         case T___builtin_expect:         \
 280         case T___builtin_huge_val:       \
 281         case T___builtin_inf:            \
 282         case T___builtin_inff:           \
 283         case T___builtin_infl:           \
 284         case T___builtin_isgreater:      \
 285         case T___builtin_isgreaterequal: \
 286         case T___builtin_isless:         \
 287         case T___builtin_islessequal:    \
 288         case T___builtin_islessgreater:  \
 289         case T___builtin_isunordered:    \
 290         case T___builtin_nan:            \
 291         case T___builtin_nanf:           \
 292         case T___builtin_nanl:           \
 293         case T___builtin_offsetof:       \
 294         case T___builtin_prefetch:       \
 295         case T___builtin_va_arg:         \
 296         case T___builtin_va_end:         \
 297         case T___builtin_va_start:       \
 298         case T___func__:                 \
 299         case T___noop:                   \
 300         case T__assume:                  \
 301         case T_delete:                   \
 302         case T_false:                    \
 303         case T_sizeof:                   \
 304         case T_throw:                    \
 305         case T_true:
 306
 307 /**
 308  * Allocate an AST node with given size and
 309  * initialize all fields with zero.
 310  */
 311 static void *allocate_ast_zero(size_t size)
 312 {
 313         void *res = allocate_ast(size);
 314         memset(res, 0, size);
 315         return res;
 316 }
 317
 318 static size_t get_entity_struct_size(entity_kind_t kind)
 319 {
 320         static const size_t sizes[] = {
 321                 [ENTITY_VARIABLE]        = sizeof(variable_t),
 322                 [ENTITY_COMPOUND_MEMBER] = sizeof(variable_t),
 323                 [ENTITY_FUNCTION]        = sizeof(function_t),
 324                 [ENTITY_TYPEDEF]         = sizeof(typedef_t),
 325                 [ENTITY_STRUCT]          = sizeof(compound_t),
 326                 [ENTITY_UNION]           = sizeof(compound_t),
 327                 [ENTITY_ENUM]            = sizeof(enum_t),
 328                 [ENTITY_ENUM_VALUE]      = sizeof(enum_value_t),
 329                 [ENTITY_LABEL]           = sizeof(label_t),
 330                 [ENTITY_LOCAL_LABEL]     = sizeof(label_t),
 331                 [ENTITY_NAMESPACE]       = sizeof(namespace_t)
 332         };
 333         assert(kind < sizeof(sizes) / sizeof(sizes[0]));
 334         assert(sizes[kind] != 0);
 335         return sizes[kind];
 336 }
 337
 338 static entity_t *allocate_entity_zero(entity_kind_t kind)
 339 {
 340         size_t    size   = get_entity_struct_size(kind);
 341         entity_t *entity = allocate_ast_zero(size);
 342         entity->kind     = kind;
 343         return entity;
 344 }
 345
 346 /**
 347  * Returns the size of a statement node.
 348  *
 349  * @param kind  the statement kind
 350  */
 351 static size_t get_statement_struct_size(statement_kind_t kind)
 352 {
 353         static const size_t sizes[] = {
 354                 [STATEMENT_INVALID]     = sizeof(invalid_statement_t),
 355                 [STATEMENT_EMPTY]       = sizeof(empty_statement_t),
 356                 [STATEMENT_COMPOUND]    = sizeof(compound_statement_t),
 357                 [STATEMENT_RETURN]      = sizeof(return_statement_t),
 358                 [STATEMENT_DECLARATION] = sizeof(declaration_statement_t),
 359                 [STATEMENT_LOCAL_LABEL] = sizeof(local_label_statement_t),
 360                 [STATEMENT_IF]          = sizeof(if_statement_t),
 361                 [STATEMENT_SWITCH]      = sizeof(switch_statement_t),
 362                 [STATEMENT_EXPRESSION]  = sizeof(expression_statement_t),
 363                 [STATEMENT_CONTINUE]    = sizeof(statement_base_t),
 364                 [STATEMENT_BREAK]       = sizeof(statement_base_t),
 365                 [STATEMENT_GOTO]        = sizeof(goto_statement_t),
 366                 [STATEMENT_LABEL]       = sizeof(label_statement_t),
 367                 [STATEMENT_CASE_LABEL]  = sizeof(case_label_statement_t),
 368                 [STATEMENT_WHILE]       = sizeof(while_statement_t),
 369                 [STATEMENT_DO_WHILE]    = sizeof(do_while_statement_t),
 370                 [STATEMENT_FOR]         = sizeof(for_statement_t),
 371                 [STATEMENT_ASM]         = sizeof(asm_statement_t),
 372                 [STATEMENT_MS_TRY]      = sizeof(ms_try_statement_t),
 373                 [STATEMENT_LEAVE]       = sizeof(leave_statement_t)
 374         };
 375         assert(kind < sizeof(sizes) / sizeof(sizes[0]));
 376         assert(sizes[kind] != 0);
 377         return sizes[kind];
 378 }
 379
 380 /**
 381  * Returns the size of an expression node.
 382  *
 383  * @param kind  the expression kind
 384  */
 385 static size_t get_expression_struct_size(expression_kind_t kind)
 386 {
 387         static const size_t sizes[] = {
 388                 [EXPR_INVALID]                 = sizeof(expression_base_t),
 389                 [EXPR_REFERENCE]               = sizeof(reference_expression_t),
 390                 [EXPR_REFERENCE_ENUM_VALUE]    = sizeof(reference_expression_t),
 391                 [EXPR_CONST]                   = sizeof(const_expression_t),
 392                 [EXPR_CHARACTER_CONSTANT]      = sizeof(const_expression_t),
 393                 [EXPR_WIDE_CHARACTER_CONSTANT] = sizeof(const_expression_t),
 394                 [EXPR_STRING_LITERAL]          = sizeof(string_literal_expression_t),
 395                 [EXPR_WIDE_STRING_LITERAL]     = sizeof(wide_string_literal_expression_t),
 396                 [EXPR_COMPOUND_LITERAL]        = sizeof(compound_literal_expression_t),
 397                 [EXPR_CALL]                    = sizeof(call_expression_t),
 398                 [EXPR_UNARY_FIRST]             = sizeof(unary_expression_t),
 399                 [EXPR_BINARY_FIRST]            = sizeof(binary_expression_t),
 400                 [EXPR_CONDITIONAL]             = sizeof(conditional_expression_t),
 401                 [EXPR_SELECT]                  = sizeof(select_expression_t),
 402                 [EXPR_ARRAY_ACCESS]            = sizeof(array_access_expression_t),
 403                 [EXPR_SIZEOF]                  = sizeof(typeprop_expression_t),
 404                 [EXPR_ALIGNOF]                 = sizeof(typeprop_expression_t),
 405                 [EXPR_CLASSIFY_TYPE]           = sizeof(classify_type_expression_t),
 406                 [EXPR_FUNCNAME]                = sizeof(funcname_expression_t),
 407                 [EXPR_BUILTIN_SYMBOL]          = sizeof(builtin_symbol_expression_t),
 408                 [EXPR_BUILTIN_CONSTANT_P]      = sizeof(builtin_constant_expression_t),
 409                 [EXPR_BUILTIN_PREFETCH]        = sizeof(builtin_prefetch_expression_t),
 410                 [EXPR_OFFSETOF]                = sizeof(offsetof_expression_t),
 411                 [EXPR_VA_START]                = sizeof(va_start_expression_t),
 412                 [EXPR_VA_ARG]                  = sizeof(va_arg_expression_t),
 413                 [EXPR_STATEMENT]               = sizeof(statement_expression_t),
 414                 [EXPR_LABEL_ADDRESS]           = sizeof(label_address_expression_t),
 415         };
 416         if (kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
 417                 return sizes[EXPR_UNARY_FIRST];
 418         }
 419         if (kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
 420                 return sizes[EXPR_BINARY_FIRST];
 421         }
 422         assert(kind < sizeof(sizes) / sizeof(sizes[0]));
 423         assert(sizes[kind] != 0);
 424         return sizes[kind];
 425 }
 426
 427 /**
 428  * Allocate a statement node of given kind and initialize all
 429  * fields with zero.
 430  */
 431 static statement_t *allocate_statement_zero(statement_kind_t kind)
 432 {
 433         size_t       size = get_statement_struct_size(kind);
 434         statement_t *res  = allocate_ast_zero(size);
 435
 436         res->base.kind            = kind;
 437         res->base.parent          = current_parent;
 438         res->base.source_position = token.source_position;
 439         return res;
 440 }
 441
 442 /**
 443  * Allocate an expression node of given kind and initialize all
 444  * fields with zero.
 445  */
 446 static expression_t *allocate_expression_zero(expression_kind_t kind)
 447 {
 448         size_t        size = get_expression_struct_size(kind);
 449         expression_t *res  = allocate_ast_zero(size);
 450
 451         res->base.kind            = kind;
 452         res->base.type            = type_error_type;
 453         res->base.source_position = token.source_position;
 454         return res;
 455 }
 456
 457 /**
 458  * Creates a new invalid expression.
 459  */
 460 static expression_t *create_invalid_expression(void)
 461 {
 462         return allocate_expression_zero(EXPR_INVALID);
 463 }
 464
 465 /**
 466  * Creates a new invalid statement.
 467  */
 468 static statement_t *create_invalid_statement(void)
 469 {
 470         return allocate_statement_zero(STATEMENT_INVALID);
 471 }
 472
 473 /**
 474  * Allocate a new empty statement.
 475  */
 476 static statement_t *create_empty_statement(void)
 477 {
 478         return allocate_statement_zero(STATEMENT_EMPTY);
 479 }
 480
 481 /**
 482  * Returns the size of a type node.
 483  *
 484  * @param kind  the type kind
 485  */
 486 static size_t get_type_struct_size(type_kind_t kind)
 487 {
 488         static const size_t sizes[] = {
 489                 [TYPE_ATOMIC]          = sizeof(atomic_type_t),
 490                 [TYPE_COMPLEX]         = sizeof(complex_type_t),
 491                 [TYPE_IMAGINARY]       = sizeof(imaginary_type_t),
 492                 [TYPE_BITFIELD]        = sizeof(bitfield_type_t),
 493                 [TYPE_COMPOUND_STRUCT] = sizeof(compound_type_t),
 494                 [TYPE_COMPOUND_UNION]  = sizeof(compound_type_t),
 495                 [TYPE_ENUM]            = sizeof(enum_type_t),
 496                 [TYPE_FUNCTION]        = sizeof(function_type_t),
 497                 [TYPE_POINTER]         = sizeof(pointer_type_t),
 498                 [TYPE_ARRAY]           = sizeof(array_type_t),
 499                 [TYPE_BUILTIN]         = sizeof(builtin_type_t),
 500                 [TYPE_TYPEDEF]         = sizeof(typedef_type_t),
 501                 [TYPE_TYPEOF]          = sizeof(typeof_type_t),
 502         };
 503         assert(sizeof(sizes) / sizeof(sizes[0]) == (int) TYPE_TYPEOF + 1);
 504         assert(kind <= TYPE_TYPEOF);
 505         assert(sizes[kind] != 0);
 506         return sizes[kind];
 507 }
 508
 509 /**
 510  * Allocate a type node of given kind and initialize all
 511  * fields with zero.
 512  *
 513  * @param kind             type kind to allocate
 514  */
 515 static type_t *allocate_type_zero(type_kind_t kind)
 516 {
 517         size_t  size = get_type_struct_size(kind);
 518         type_t *res  = obstack_alloc(type_obst, size);
 519         memset(res, 0, size);
 520         res->base.kind = kind;
 521
 522         return res;
 523 }
 524
 525 /**
 526  * Returns the size of an initializer node.
 527  *
 528  * @param kind  the initializer kind
 529  */
 530 static size_t get_initializer_size(initializer_kind_t kind)
 531 {
 532         static const size_t sizes[] = {
 533                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 534                 [INITIALIZER_STRING]      = sizeof(initializer_string_t),
 535                 [INITIALIZER_WIDE_STRING] = sizeof(initializer_wide_string_t),
 536                 [INITIALIZER_LIST]        = sizeof(initializer_list_t),
 537                 [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
 538         };
 539         assert(kind < sizeof(sizes) / sizeof(*sizes));
 540         assert(sizes[kind] != 0);
 541         return sizes[kind];
 542 }
 543
 544 /**
 545  * Allocate an initializer node of given kind and initialize all
 546  * fields with zero.
 547  */
 548 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 549 {
 550         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 551         result->kind          = kind;
 552
 553         return result;
 554 }
 555
 556 /**
 557  * Free a type from the type obstack.
 558  */
 559 static void free_type(void *type)
 560 {
 561         obstack_free(type_obst, type);
 562 }
 563
 564 /**
 565  * Returns the index of the top element of the environment stack.
 566  */
 567 static size_t environment_top(void)
 568 {
 569         return ARR_LEN(environment_stack);
 570 }
 571
 572 /**
 573  * Returns the index of the top element of the global label stack.
 574  */
 575 static size_t label_top(void)
 576 {
 577         return ARR_LEN(label_stack);
 578 }
 579
 580 /**
 581  * Return the next token.
 582  */
 583 static inline void next_token(void)
 584 {
 585         token                              = lookahead_buffer[lookahead_bufpos];
 586         lookahead_buffer[lookahead_bufpos] = lexer_token;
 587         lexer_next_token();
 588
 589         lookahead_bufpos = (lookahead_bufpos+1) % MAX_LOOKAHEAD;
 590
 591 #ifdef PRINT_TOKENS
 592         print_token(stderr, &token);
 593         fprintf(stderr, "\n");
 594 #endif
 595 }
 596
 597 /**
 598  * Return the next token with a given lookahead.
 599  */
 600 static inline const token_t *look_ahead(int num)
 601 {
 602         assert(num > 0 && num <= MAX_LOOKAHEAD);
 603         int pos = (lookahead_bufpos+num-1) % MAX_LOOKAHEAD;
 604         return &lookahead_buffer[pos];
 605 }
 606
 607 /**
 608  * Adds a token to the token anchor set (a multi-set).
 609  */
 610 static void add_anchor_token(int token_type)
 611 {
 612         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 613         ++token_anchor_set[token_type];
 614 }
 615
 616 static int save_and_reset_anchor_state(int token_type)
 617 {
 618         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 619         int count = token_anchor_set[token_type];
 620         token_anchor_set[token_type] = 0;
 621         return count;
 622 }
 623
 624 static void restore_anchor_state(int token_type, int count)
 625 {
 626         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 627         token_anchor_set[token_type] = count;
 628 }
 629
 630 /**
 631  * Remove a token from the token anchor set (a multi-set).
 632  */
 633 static void rem_anchor_token(int token_type)
 634 {
 635         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 636         assert(token_anchor_set[token_type] != 0);
 637         --token_anchor_set[token_type];
 638 }
 639
 640 static bool at_anchor(void)
 641 {
 642         if (token.type < 0)
 643                 return false;
 644         return token_anchor_set[token.type];
 645 }
 646
 647 /**
 648  * Eat tokens until a matching token is found.
 649  */
 650 static void eat_until_matching_token(int type)
 651 {
 652         int end_token;
 653         switch (type) {
 654                 case '(': end_token = ')';  break;
 655                 case '{': end_token = '}';  break;
 656                 case '[': end_token = ']';  break;
 657                 default:  end_token = type; break;
 658         }
 659
 660         unsigned parenthesis_count = 0;
 661         unsigned brace_count       = 0;
 662         unsigned bracket_count     = 0;
 663         while (token.type        != end_token ||
 664                parenthesis_count != 0         ||
 665                brace_count       != 0         ||
 666                bracket_count     != 0) {
 667                 switch (token.type) {
 668                 case T_EOF: return;
 669                 case '(': ++parenthesis_count; break;
 670                 case '{': ++brace_count;       break;
 671                 case '[': ++bracket_count;     break;
 672
 673                 case ')':
 674                         if (parenthesis_count > 0)
 675                                 --parenthesis_count;
 676                         goto check_stop;
 677
 678                 case '}':
 679                         if (brace_count > 0)
 680                                 --brace_count;
 681                         goto check_stop;
 682
 683                 case ']':
 684                         if (bracket_count > 0)
 685                                 --bracket_count;
 686 check_stop:
 687                         if (token.type        == end_token &&
 688                             parenthesis_count == 0         &&
 689                             brace_count       == 0         &&
 690                             bracket_count     == 0)
 691                                 return;
 692                         break;
 693
 694                 default:
 695                         break;
 696                 }
 697                 next_token();
 698         }
 699 }
 700
 701 /**
 702  * Eat input tokens until an anchor is found.
 703  */
 704 static void eat_until_anchor(void)
 705 {
 706         while (token_anchor_set[token.type] == 0) {
 707                 if (token.type == '(' || token.type == '{' || token.type == '[')
 708                         eat_until_matching_token(token.type);
 709                 next_token();
 710         }
 711 }
 712
 713 static void eat_block(void)
 714 {
 715         eat_until_matching_token('{');
 716         if (token.type == '}')
 717                 next_token();
 718 }
 719
 720 #define eat(token_type)  do { assert(token.type == (token_type)); next_token(); } while (0)
 721
 722 /**
 723  * Report a parse error because an expected token was not found.
 724  */
 725 static
 726 #if defined __GNUC__ && __GNUC__ >= 4
 727 __attribute__((sentinel))
 728 #endif
 729 void parse_error_expected(const char *message, ...)
 730 {
 731         if (message != NULL) {
 732                 errorf(HERE, "%s", message);
 733         }
 734         va_list ap;
 735         va_start(ap, message);
 736         errorf(HERE, "got %K, expected %#k", &token, &ap, ", ");
 737         va_end(ap);
 738 }
 739
 740 /**
 741  * Report a type error.
 742  */
 743 static void type_error(const char *msg, const source_position_t *source_position,
 744                        type_t *type)
 745 {
 746         errorf(source_position, "%s, but found type '%T'", msg, type);
 747 }
 748
 749 /**
 750  * Report an incompatible type.
 751  */
 752 static void type_error_incompatible(const char *msg,
 753                 const source_position_t *source_position, type_t *type1, type_t *type2)
 754 {
 755         errorf(source_position, "%s, incompatible types: '%T' - '%T'",
 756                msg, type1, type2);
 757 }
 758
 759 /**
 760  * Expect the the current token is the expected token.
 761  * If not, generate an error, eat the current statement,
 762  * and goto the end_error label.
 763  */
 764 #define expect(expected)                                  \
 765         do {                                                  \
 766                 if (UNLIKELY(token.type != (expected))) {         \
 767                         parse_error_expected(NULL, (expected), NULL); \
 768                         add_anchor_token(expected);                   \
 769                         eat_until_anchor();                           \
 770                         if (token.type == expected)                   \
 771                                 next_token();                             \
 772                         rem_anchor_token(expected);                   \
 773                         goto end_error;                               \
 774                 }                                                 \
 775                 next_token();                                     \
 776         } while (0)
 777
 778 static void scope_push(scope_t *new_scope)
 779 {
 780         if (current_scope != NULL) {
 781                 new_scope->depth = current_scope->depth + 1;
 782         }
 783         new_scope->parent = current_scope;
 784         current_scope     = new_scope;
 785 }
 786
 787 static void scope_pop(void)
 788 {
 789         current_scope = current_scope->parent;
 790 }
 791
 792 /**
 793  * Search an entity by its symbol in a given namespace.
 794  */
 795 static entity_t *get_entity(const symbol_t *const symbol,
 796                             namespace_tag_t namespc)
 797 {
 798         entity_t *entity = symbol->entity;
 799         for (; entity != NULL; entity = entity->base.symbol_next) {
 800                 if (entity->base.namespc == namespc)
 801                         return entity;
 802         }
 803
 804         return NULL;
 805 }
 806
 807 /**
 808  * pushs an entity on the environment stack and links the corresponding symbol
 809  * it.
 810  */
 811 static void stack_push(stack_entry_t **stack_ptr, entity_t *entity)
 812 {
 813         symbol_t           *symbol  = entity->base.symbol;
 814         entity_namespace_t  namespc = entity->base.namespc;
 815         assert(namespc != NAMESPACE_INVALID);
 816
 817         /* replace/add entity into entity list of the symbol */
 818         entity_t **anchor;
 819         entity_t  *iter;
 820         for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 821                 iter = *anchor;
 822                 if (iter == NULL)
 823                         break;
 824
 825                 /* replace an entry? */
 826                 if (iter->base.namespc == namespc) {
 827                         entity->base.symbol_next = iter->base.symbol_next;
 828                         break;
 829                 }
 830         }
 831         *anchor = entity;
 832
 833         /* remember old declaration */
 834         stack_entry_t entry;
 835         entry.symbol     = symbol;
 836         entry.old_entity = iter;
 837         entry.namespc    = namespc;
 838         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 839 }
 840
 841 /**
 842  * Push an entity on the environment stack.
 843  */
 844 static void environment_push(entity_t *entity)
 845 {
 846         assert(entity->base.source_position.input_name != NULL);
 847         assert(entity->base.parent_scope != NULL);
 848         stack_push(&environment_stack, entity);
 849 }
 850
 851 /**
 852  * Push a declaration on the global label stack.
 853  *
 854  * @param declaration  the declaration
 855  */
 856 static void label_push(entity_t *label)
 857 {
 858         /* we abuse the parameters scope as parent for the labels */
 859         label->base.parent_scope = &current_function->parameters;
 860         stack_push(&label_stack, label);
 861 }
 862
 863 /**
 864  * pops symbols from the environment stack until @p new_top is the top element
 865  */
 866 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 867 {
 868         stack_entry_t *stack = *stack_ptr;
 869         size_t         top   = ARR_LEN(stack);
 870         size_t         i;
 871
 872         assert(new_top <= top);
 873         if (new_top == top)
 874                 return;
 875
 876         for (i = top; i > new_top; --i) {
 877                 stack_entry_t *entry = &stack[i - 1];
 878
 879                 entity_t           *old_entity = entry->old_entity;
 880                 symbol_t           *symbol     = entry->symbol;
 881                 entity_namespace_t  namespc    = entry->namespc;
 882
 883                 /* replace with old_entity/remove */
 884                 entity_t **anchor;
 885                 entity_t  *iter;
 886                 for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 887                         iter = *anchor;
 888                         assert(iter != NULL);
 889                         /* replace an entry? */
 890                         if (iter->base.namespc == namespc)
 891                                 break;
 892                 }
 893
 894                 /* restore definition from outer scopes (if there was one) */
 895                 if (old_entity != NULL) {
 896                         old_entity->base.symbol_next = iter->base.symbol_next;
 897                         *anchor                      = old_entity;
 898                 } else {
 899                         /* remove entry from list */
 900                         *anchor = iter->base.symbol_next;
 901                 }
 902         }
 903
 904         ARR_SHRINKLEN(*stack_ptr, (int) new_top);
 905 }
 906
 907 /**
 908  * Pop all entries from the environment stack until the new_top
 909  * is reached.
 910  *
 911  * @param new_top  the new stack top
 912  */
 913 static void environment_pop_to(size_t new_top)
 914 {
 915         stack_pop_to(&environment_stack, new_top);
 916 }
 917
 918 /**
 919  * Pop all entries from the global label stack until the new_top
 920  * is reached.
 921  *
 922  * @param new_top  the new stack top
 923  */
 924 static void label_pop_to(size_t new_top)
 925 {
 926         stack_pop_to(&label_stack, new_top);
 927 }
 928
 929 static int get_akind_rank(atomic_type_kind_t akind)
 930 {
 931         return (int) akind;
 932 }
 933
 934 static int get_rank(const type_t *type)
 935 {
 936         assert(!is_typeref(type));
 937         /* The C-standard allows promoting enums to int or unsigned int (see § 7.2.2
 938          * and esp. footnote 108). However we can't fold constants (yet), so we
 939          * can't decide whether unsigned int is possible, while int always works.
 940          * (unsigned int would be preferable when possible... for stuff like
 941          *  struct { enum { ... } bla : 4; } ) */
 942         if (type->kind == TYPE_ENUM)
 943                 return get_akind_rank(ATOMIC_TYPE_INT);
 944
 945         assert(type->kind == TYPE_ATOMIC);
 946         return get_akind_rank(type->atomic.akind);
 947 }
 948
 949 static type_t *promote_integer(type_t *type)
 950 {
 951         if (type->kind == TYPE_BITFIELD)
 952                 type = type->bitfield.base_type;
 953
 954         if (get_rank(type) < get_akind_rank(ATOMIC_TYPE_INT))
 955                 type = type_int;
 956
 957         return type;
 958 }
 959
 960 /**
 961  * Create a cast expression.
 962  *
 963  * @param expression  the expression to cast
 964  * @param dest_type   the destination type
 965  */
 966 static expression_t *create_cast_expression(expression_t *expression,
 967                                             type_t *dest_type)
 968 {
 969         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST_IMPLICIT);
 970
 971         cast->unary.value = expression;
 972         cast->base.type   = dest_type;
 973
 974         return cast;
 975 }
 976
 977 /**
 978  * Check if a given expression represents the 0 pointer constant.
 979  */
 980 static bool is_null_pointer_constant(const expression_t *expression)
 981 {
 982         /* skip void* cast */
 983         if (expression->kind == EXPR_UNARY_CAST
 984                         || expression->kind == EXPR_UNARY_CAST_IMPLICIT) {
 985                 expression = expression->unary.value;
 986         }
 987
 988         /* TODO: not correct yet, should be any constant integer expression
 989          * which evaluates to 0 */
 990         if (expression->kind != EXPR_CONST)
 991                 return false;
 992
 993         type_t *const type = skip_typeref(expression->base.type);
 994         if (!is_type_integer(type))
 995                 return false;
 996
 997         return expression->conste.v.int_value == 0;
 998 }
 999
1000 /**
1001  * Create an implicit cast expression.
1002  *
1003  * @param expression  the expression to cast
1004  * @param dest_type   the destination type
1005  */
1006 static expression_t *create_implicit_cast(expression_t *expression,
1007                                           type_t *dest_type)
1008 {
1009         type_t *const source_type = expression->base.type;
1010
1011         if (source_type == dest_type)
1012                 return expression;
1013
1014         return create_cast_expression(expression, dest_type);
1015 }
1016
1017 typedef enum assign_error_t {
1018         ASSIGN_SUCCESS,
1019         ASSIGN_ERROR_INCOMPATIBLE,
1020         ASSIGN_ERROR_POINTER_QUALIFIER_MISSING,
1021         ASSIGN_WARNING_POINTER_INCOMPATIBLE,
1022         ASSIGN_WARNING_POINTER_FROM_INT,
1023         ASSIGN_WARNING_INT_FROM_POINTER
1024 } assign_error_t;
1025
1026 static void report_assign_error(assign_error_t error, type_t *orig_type_left,
1027                                 const expression_t *const right,
1028                                 const char *context,
1029                                 const source_position_t *source_position)
1030 {
1031         type_t *const orig_type_right = right->base.type;
1032         type_t *const type_left       = skip_typeref(orig_type_left);
1033         type_t *const type_right      = skip_typeref(orig_type_right);
1034
1035         switch (error) {
1036         case ASSIGN_SUCCESS:
1037                 return;
1038         case ASSIGN_ERROR_INCOMPATIBLE:
1039                 errorf(source_position,
1040                        "destination type '%T' in %s is incompatible with type '%T'",
1041                        orig_type_left, context, orig_type_right);
1042                 return;
1043
1044         case ASSIGN_ERROR_POINTER_QUALIFIER_MISSING: {
1045                 if (warning.other) {
1046                         type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
1047                         type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
1048
1049                         /* the left type has all qualifiers from the right type */
1050                         unsigned missing_qualifiers
1051                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
1052                         warningf(source_position,
1053                                         "destination type '%T' in %s from type '%T' lacks qualifiers '%Q' in pointer target type",
1054                                         orig_type_left, context, orig_type_right, missing_qualifiers);
1055                 }
1056                 return;
1057         }
1058
1059         case ASSIGN_WARNING_POINTER_INCOMPATIBLE:
1060                 if (warning.other) {
1061                         warningf(source_position,
1062                                         "destination type '%T' in %s is incompatible with '%E' of type '%T'",
1063                                         orig_type_left, context, right, orig_type_right);
1064                 }
1065                 return;
1066
1067         case ASSIGN_WARNING_POINTER_FROM_INT:
1068                 if (warning.other) {
1069                         warningf(source_position,
1070                                         "%s makes pointer '%T' from integer '%T' without a cast",
1071                                         context, orig_type_left, orig_type_right);
1072                 }
1073                 return;
1074
1075         case ASSIGN_WARNING_INT_FROM_POINTER:
1076                 if (warning.other) {
1077                         warningf(source_position,
1078                                         "%s makes integer '%T' from pointer '%T' without a cast",
1079                                         context, orig_type_left, orig_type_right);
1080                 }
1081                 return;
1082
1083         default:
1084                 panic("invalid error value");
1085         }
1086 }
1087
1088 /** Implements the rules from § 6.5.16.1 */
1089 static assign_error_t semantic_assign(type_t *orig_type_left,
1090                                       const expression_t *const right)
1091 {
1092         type_t *const orig_type_right = right->base.type;
1093         type_t *const type_left       = skip_typeref(orig_type_left);
1094         type_t *const type_right      = skip_typeref(orig_type_right);
1095
1096         if (is_type_pointer(type_left)) {
1097                 if (is_null_pointer_constant(right)) {
1098                         return ASSIGN_SUCCESS;
1099                 } else if (is_type_pointer(type_right)) {
1100                         type_t *points_to_left
1101                                 = skip_typeref(type_left->pointer.points_to);
1102                         type_t *points_to_right
1103                                 = skip_typeref(type_right->pointer.points_to);
1104                         assign_error_t res = ASSIGN_SUCCESS;
1105
1106                         /* the left type has all qualifiers from the right type */
1107                         unsigned missing_qualifiers
1108                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
1109                         if (missing_qualifiers != 0) {
1110                                 res = ASSIGN_ERROR_POINTER_QUALIFIER_MISSING;
1111                         }
1112
1113                         points_to_left  = get_unqualified_type(points_to_left);
1114                         points_to_right = get_unqualified_type(points_to_right);
1115
1116                         if (is_type_atomic(points_to_left, ATOMIC_TYPE_VOID))
1117                                 return res;
1118
1119                         if (is_type_atomic(points_to_right, ATOMIC_TYPE_VOID)) {
1120                                 /* ISO/IEC 14882:1998(E) §C.1.2:6 */
1121                                 return c_mode & _CXX ? ASSIGN_ERROR_INCOMPATIBLE : res;
1122                         }
1123
1124                         if (!types_compatible(points_to_left, points_to_right)) {
1125                                 return ASSIGN_WARNING_POINTER_INCOMPATIBLE;
1126                         }
1127
1128                         return res;
1129                 } else if (is_type_integer(type_right)) {
1130                         return ASSIGN_WARNING_POINTER_FROM_INT;
1131                 }
1132         } else if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
1133             (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
1134                 && is_type_pointer(type_right))) {
1135                 return ASSIGN_SUCCESS;
1136         } else if ((is_type_compound(type_left)  && is_type_compound(type_right))
1137                         || (is_type_builtin(type_left) && is_type_builtin(type_right))) {
1138                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
1139                 type_t *const unqual_type_right = get_unqualified_type(type_right);
1140                 if (types_compatible(unqual_type_left, unqual_type_right)) {
1141                         return ASSIGN_SUCCESS;
1142                 }
1143         } else if (is_type_integer(type_left) && is_type_pointer(type_right)) {
1144                 return ASSIGN_WARNING_INT_FROM_POINTER;
1145         }
1146
1147         if (!is_type_valid(type_left) || !is_type_valid(type_right))
1148                 return ASSIGN_SUCCESS;
1149
1150         return ASSIGN_ERROR_INCOMPATIBLE;
1151 }
1152
1153 static expression_t *parse_constant_expression(void)
1154 {
1155         expression_t *result = parse_sub_expression(PREC_CONDITIONAL);
1156
1157         if (!is_constant_expression(result)) {
1158                 errorf(&result->base.source_position,
1159                        "expression '%E' is not constant\n", result);
1160         }
1161
1162         return result;
1163 }
1164
1165 static expression_t *parse_assignment_expression(void)
1166 {
1167         return parse_sub_expression(PREC_ASSIGNMENT);
1168 }
1169
1170 static string_t parse_string_literals(void)
1171 {
1172         assert(token.type == T_STRING_LITERAL);
1173         string_t result = token.v.string;
1174
1175         next_token();
1176
1177         while (token.type == T_STRING_LITERAL) {
1178                 result = concat_strings(&result, &token.v.string);
1179                 next_token();
1180         }
1181
1182         return result;
1183 }
1184
1185 static const char *const gnu_attribute_names[GNU_AK_LAST] = {
1186         [GNU_AK_CONST]                  = "const",
1187         [GNU_AK_VOLATILE]               = "volatile",
1188         [GNU_AK_CDECL]                  = "cdecl",
1189         [GNU_AK_STDCALL]                = "stdcall",
1190         [GNU_AK_FASTCALL]               = "fastcall",
1191         [GNU_AK_DEPRECATED]             = "deprecated",
1192         [GNU_AK_NOINLINE]               = "noinline",
1193         [GNU_AK_NORETURN]               = "noreturn",
1194         [GNU_AK_NAKED]                  = "naked",
1195         [GNU_AK_PURE]                   = "pure",
1196         [GNU_AK_ALWAYS_INLINE]          = "always_inline",
1197         [GNU_AK_MALLOC]                 = "malloc",
1198         [GNU_AK_WEAK]                   = "weak",
1199         [GNU_AK_CONSTRUCTOR]            = "constructor",
1200         [GNU_AK_DESTRUCTOR]             = "destructor",
1201         [GNU_AK_NOTHROW]                = "nothrow",
1202         [GNU_AK_TRANSPARENT_UNION]      = "transparent_union",
1203         [GNU_AK_COMMON]                 = "common",
1204         [GNU_AK_NOCOMMON]               = "nocommon",
1205         [GNU_AK_PACKED]                 = "packed",
1206         [GNU_AK_SHARED]                 = "shared",
1207         [GNU_AK_NOTSHARED]              = "notshared",
1208         [GNU_AK_USED]                   = "used",
1209         [GNU_AK_UNUSED]                 = "unused",
1210         [GNU_AK_NO_INSTRUMENT_FUNCTION] = "no_instrument_function",
1211         [GNU_AK_WARN_UNUSED_RESULT]     = "warn_unused_result",
1212         [GNU_AK_LONGCALL]               = "longcall",
1213         [GNU_AK_SHORTCALL]              = "shortcall",
1214         [GNU_AK_LONG_CALL]              = "long_call",
1215         [GNU_AK_SHORT_CALL]             = "short_call",
1216         [GNU_AK_FUNCTION_VECTOR]        = "function_vector",
1217         [GNU_AK_INTERRUPT]              = "interrupt",
1218         [GNU_AK_INTERRUPT_HANDLER]      = "interrupt_handler",
1219         [GNU_AK_NMI_HANDLER]            = "nmi_handler",
1220         [GNU_AK_NESTING]                = "nesting",
1221         [GNU_AK_NEAR]                   = "near",
1222         [GNU_AK_FAR]                    = "far",
1223         [GNU_AK_SIGNAL]                 = "signal",
1224         [GNU_AK_EIGTHBIT_DATA]          = "eightbit_data",
1225         [GNU_AK_TINY_DATA]              = "tiny_data",
1226         [GNU_AK_SAVEALL]                = "saveall",
1227         [GNU_AK_FLATTEN]                = "flatten",
1228         [GNU_AK_SSEREGPARM]             = "sseregparm",
1229         [GNU_AK_EXTERNALLY_VISIBLE]     = "externally_visible",
1230         [GNU_AK_RETURN_TWICE]           = "return_twice",
1231         [GNU_AK_MAY_ALIAS]              = "may_alias",
1232         [GNU_AK_MS_STRUCT]              = "ms_struct",
1233         [GNU_AK_GCC_STRUCT]             = "gcc_struct",
1234         [GNU_AK_DLLIMPORT]              = "dllimport",
1235         [GNU_AK_DLLEXPORT]              = "dllexport",
1236         [GNU_AK_ALIGNED]                = "aligned",
1237         [GNU_AK_ALIAS]                  = "alias",
1238         [GNU_AK_SECTION]                = "section",
1239         [GNU_AK_FORMAT]                 = "format",
1240         [GNU_AK_FORMAT_ARG]             = "format_arg",
1241         [GNU_AK_WEAKREF]                = "weakref",
1242         [GNU_AK_NONNULL]                = "nonnull",
1243         [GNU_AK_TLS_MODEL]              = "tls_model",
1244         [GNU_AK_VISIBILITY]             = "visibility",
1245         [GNU_AK_REGPARM]                = "regparm",
1246         [GNU_AK_MODE]                   = "mode",
1247         [GNU_AK_MODEL]                  = "model",
1248         [GNU_AK_TRAP_EXIT]              = "trap_exit",
1249         [GNU_AK_SP_SWITCH]              = "sp_switch",
1250         [GNU_AK_SENTINEL]               = "sentinel"
1251 };
1252
1253 /**
1254  * compare two string, ignoring double underscores on the second.
1255  */
1256 static int strcmp_underscore(const char *s1, const char *s2)
1257 {
1258         if (s2[0] == '_' && s2[1] == '_') {
1259                 size_t len2 = strlen(s2);
1260                 size_t len1 = strlen(s1);
1261                 if (len1 == len2-4 && s2[len2-2] == '_' && s2[len2-1] == '_') {
1262                         return strncmp(s1, s2+2, len2-4);
1263                 }
1264         }
1265
1266         return strcmp(s1, s2);
1267 }
1268
1269 /**
1270  * Allocate a new gnu temporal attribute.
1271  */
1272 static gnu_attribute_t *allocate_gnu_attribute(gnu_attribute_kind_t kind)
1273 {
1274         gnu_attribute_t *attribute = obstack_alloc(&temp_obst, sizeof(*attribute));
1275         attribute->kind            = kind;
1276         attribute->next            = NULL;
1277         attribute->invalid         = false;
1278         attribute->have_arguments  = false;
1279
1280         return attribute;
1281 }
1282
1283 /**
1284  * parse one constant expression argument.
1285  */
1286 static void parse_gnu_attribute_const_arg(gnu_attribute_t *attribute)
1287 {
1288         expression_t *expression;
1289         add_anchor_token(')');
1290         expression = parse_constant_expression();
1291         rem_anchor_token(')');
1292         expect(')');
1293         attribute->u.argument = fold_constant(expression);
1294         return;
1295 end_error:
1296         attribute->invalid = true;
1297 }
1298
1299 /**
1300  * parse a list of constant expressions arguments.
1301  */
1302 static void parse_gnu_attribute_const_arg_list(gnu_attribute_t *attribute)
1303 {
1304         argument_list_t **list = &attribute->u.arguments;
1305         argument_list_t  *entry;
1306         expression_t     *expression;
1307         add_anchor_token(')');
1308         add_anchor_token(',');
1309         while (true) {
1310                 expression = parse_constant_expression();
1311                 entry = obstack_alloc(&temp_obst, sizeof(entry));
1312                 entry->argument = fold_constant(expression);
1313                 entry->next     = NULL;
1314                 *list = entry;
1315                 list = &entry->next;
1316                 if (token.type != ',')
1317                         break;
1318                 next_token();
1319         }
1320         rem_anchor_token(',');
1321         rem_anchor_token(')');
1322         expect(')');
1323         return;
1324 end_error:
1325         attribute->invalid = true;
1326 }
1327
1328 /**
1329  * parse one string literal argument.
1330  */
1331 static void parse_gnu_attribute_string_arg(gnu_attribute_t *attribute,
1332                                            string_t *string)
1333 {
1334         add_anchor_token('(');
1335         if (token.type != T_STRING_LITERAL) {
1336                 parse_error_expected("while parsing attribute directive",
1337                                      T_STRING_LITERAL, NULL);
1338                 goto end_error;
1339         }
1340         *string = parse_string_literals();
1341         rem_anchor_token('(');
1342         expect(')');
1343         return;
1344 end_error:
1345         attribute->invalid = true;
1346 }
1347
1348 /**
1349  * parse one tls model.
1350  */
1351 static void parse_gnu_attribute_tls_model_arg(gnu_attribute_t *attribute)
1352 {
1353         static const char *const tls_models[] = {
1354                 "global-dynamic",
1355                 "local-dynamic",
1356                 "initial-exec",
1357                 "local-exec"
1358         };
1359         string_t string = { NULL, 0 };
1360         parse_gnu_attribute_string_arg(attribute, &string);
1361         if (string.begin != NULL) {
1362                 for (size_t i = 0; i < 4; ++i) {
1363                         if (strcmp(tls_models[i], string.begin) == 0) {
1364                                 attribute->u.value = i;
1365                                 return;
1366                         }
1367                 }
1368                 errorf(HERE, "'%s' is an unrecognized tls model", string.begin);
1369         }
1370         attribute->invalid = true;
1371 }
1372
1373 /**
1374  * parse one tls model.
1375  */
1376 static void parse_gnu_attribute_visibility_arg(gnu_attribute_t *attribute)
1377 {
1378         static const char *const visibilities[] = {
1379                 "default",
1380                 "protected",
1381                 "hidden",
1382                 "internal"
1383         };
1384         string_t string = { NULL, 0 };
1385         parse_gnu_attribute_string_arg(attribute, &string);
1386         if (string.begin != NULL) {
1387                 for (size_t i = 0; i < 4; ++i) {
1388                         if (strcmp(visibilities[i], string.begin) == 0) {
1389                                 attribute->u.value = i;
1390                                 return;
1391                         }
1392                 }
1393                 errorf(HERE, "'%s' is an unrecognized visibility", string.begin);
1394         }
1395         attribute->invalid = true;
1396 }
1397
1398 /**
1399  * parse one (code) model.
1400  */
1401 static void parse_gnu_attribute_model_arg(gnu_attribute_t *attribute)
1402 {
1403         static const char *const visibilities[] = {
1404                 "small",
1405                 "medium",
1406                 "large"
1407         };
1408         string_t string = { NULL, 0 };
1409         parse_gnu_attribute_string_arg(attribute, &string);
1410         if (string.begin != NULL) {
1411                 for (int i = 0; i < 3; ++i) {
1412                         if (strcmp(visibilities[i], string.begin) == 0) {
1413                                 attribute->u.value = i;
1414                                 return;
1415                         }
1416                 }
1417                 errorf(HERE, "'%s' is an unrecognized model", string.begin);
1418         }
1419         attribute->invalid = true;
1420 }
1421
1422 static void parse_gnu_attribute_mode_arg(gnu_attribute_t *attribute)
1423 {
1424         /* TODO: find out what is allowed here... */
1425
1426         /* at least: byte, word, pointer, list of machine modes
1427          * __XXX___ is interpreted as XXX */
1428         add_anchor_token(')');
1429
1430         if (token.type != T_IDENTIFIER) {
1431                 expect(T_IDENTIFIER);
1432         }
1433
1434         /* This isn't really correct, the backend should provide a list of machine
1435          * specific modes (according to gcc philosophy that is...) */
1436         const char *symbol_str = token.v.symbol->string;
1437         if (strcmp_underscore("QI",   symbol_str) == 0 ||
1438             strcmp_underscore("byte", symbol_str) == 0) {
1439                 attribute->u.akind = ATOMIC_TYPE_CHAR;
1440         } else if (strcmp_underscore("HI", symbol_str) == 0) {
1441                 attribute->u.akind = ATOMIC_TYPE_SHORT;
1442         } else if (strcmp_underscore("SI",      symbol_str) == 0
1443                 || strcmp_underscore("word",    symbol_str) == 0
1444                 || strcmp_underscore("pointer", symbol_str) == 0) {
1445                 attribute->u.akind = ATOMIC_TYPE_INT;
1446         } else if (strcmp_underscore("DI", symbol_str) == 0) {
1447                 attribute->u.akind = ATOMIC_TYPE_LONGLONG;
1448         } else {
1449                 if (warning.other)
1450                         warningf(HERE, "ignoring unknown mode '%s'", symbol_str);
1451                 attribute->invalid = true;
1452         }
1453         next_token();
1454
1455         rem_anchor_token(')');
1456         expect(')');
1457         return;
1458 end_error:
1459         attribute->invalid = true;
1460 }
1461
1462 /**
1463  * parse one interrupt argument.
1464  */
1465 static void parse_gnu_attribute_interrupt_arg(gnu_attribute_t *attribute)
1466 {
1467         static const char *const interrupts[] = {
1468                 "IRQ",
1469                 "FIQ",
1470                 "SWI",
1471                 "ABORT",
1472                 "UNDEF"
1473         };
1474         string_t string = { NULL, 0 };
1475         parse_gnu_attribute_string_arg(attribute, &string);
1476         if (string.begin != NULL) {
1477                 for (size_t i = 0; i < 5; ++i) {
1478                         if (strcmp(interrupts[i], string.begin) == 0) {
1479                                 attribute->u.value = i;
1480                                 return;
1481                         }
1482                 }
1483                 errorf(HERE, "'%s' is not an interrupt", string.begin);
1484         }
1485         attribute->invalid = true;
1486 }
1487
1488 /**
1489  * parse ( identifier, const expression, const expression )
1490  */
1491 static void parse_gnu_attribute_format_args(gnu_attribute_t *attribute)
1492 {
1493         static const char *const format_names[] = {
1494                 "printf",
1495                 "scanf",
1496                 "strftime",
1497                 "strfmon"
1498         };
1499         int i;
1500
1501         if (token.type != T_IDENTIFIER) {
1502                 parse_error_expected("while parsing format attribute directive", T_IDENTIFIER, NULL);
1503                 goto end_error;
1504         }
1505         const char *name = token.v.symbol->string;
1506         for (i = 0; i < 4; ++i) {
1507                 if (strcmp_underscore(format_names[i], name) == 0)
1508                         break;
1509         }
1510         if (i >= 4) {
1511                 if (warning.attribute)
1512                         warningf(HERE, "'%s' is an unrecognized format function type", name);
1513         }
1514         next_token();
1515
1516         expect(',');
1517         add_anchor_token(')');
1518         add_anchor_token(',');
1519         parse_constant_expression();
1520         rem_anchor_token(',');
1521         rem_anchor_token(')');
1522
1523         expect(',');
1524         add_anchor_token(')');
1525         parse_constant_expression();
1526         rem_anchor_token(')');
1527         expect(')');
1528         return;
1529 end_error:
1530         attribute->u.value = true;
1531 }
1532
1533 static void check_no_argument(gnu_attribute_t *attribute, const char *name)
1534 {
1535         if (!attribute->have_arguments)
1536                 return;
1537
1538         /* should have no arguments */
1539         errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1540         eat_until_matching_token('(');
1541         /* we have already consumed '(', so we stop before ')', eat it */
1542         eat(')');
1543         attribute->invalid = true;
1544 }
1545
1546 /**
1547  * Parse one GNU attribute.
1548  *
1549  * Note that attribute names can be specified WITH or WITHOUT
1550  * double underscores, ie const or __const__.
1551  *
1552  * The following attributes are parsed without arguments
1553  *  const
1554  *  volatile
1555  *  cdecl
1556  *  stdcall
1557  *  fastcall
1558  *  deprecated
1559  *  noinline
1560  *  noreturn
1561  *  naked
1562  *  pure
1563  *  always_inline
1564  *  malloc
1565  *  weak
1566  *  constructor
1567  *  destructor
1568  *  nothrow
1569  *  transparent_union
1570  *  common
1571  *  nocommon
1572  *  packed
1573  *  shared
1574  *  notshared
1575  *  used
1576  *  unused
1577  *  no_instrument_function
1578  *  warn_unused_result
1579  *  longcall
1580  *  shortcall
1581  *  long_call
1582  *  short_call
1583  *  function_vector
1584  *  interrupt_handler
1585  *  nmi_handler
1586  *  nesting
1587  *  near
1588  *  far
1589  *  signal
1590  *  eightbit_data
1591  *  tiny_data
1592  *  saveall
1593  *  flatten
1594  *  sseregparm
1595  *  externally_visible
1596  *  return_twice
1597  *  may_alias
1598  *  ms_struct
1599  *  gcc_struct
1600  *  dllimport
1601  *  dllexport
1602  *
1603  * The following attributes are parsed with arguments
1604  *  aligned( const expression )
1605  *  alias( string literal )
1606  *  section( string literal )
1607  *  format( identifier, const expression, const expression )
1608  *  format_arg( const expression )
1609  *  tls_model( string literal )
1610  *  visibility( string literal )
1611  *  regparm( const expression )
1612  *  model( string leteral )
1613  *  trap_exit( const expression )
1614  *  sp_switch( string literal )
1615  *
1616  * The following attributes might have arguments
1617  *  weak_ref( string literal )
1618  *  non_null( const expression // ',' )
1619  *  interrupt( string literal )
1620  *  sentinel( constant expression )
1621  */
1622 static decl_modifiers_t parse_gnu_attribute(gnu_attribute_t **attributes)
1623 {
1624         gnu_attribute_t *head      = *attributes;
1625         gnu_attribute_t *last      = *attributes;
1626         decl_modifiers_t modifiers = 0;
1627         gnu_attribute_t *attribute;
1628
1629         eat(T___attribute__);
1630         expect('(');
1631         expect('(');
1632
1633         if (token.type != ')') {
1634                 /* find the end of the list */
1635                 if (last != NULL) {
1636                         while (last->next != NULL)
1637                                 last = last->next;
1638                 }
1639
1640                 /* non-empty attribute list */
1641                 while (true) {
1642                         const char *name;
1643                         if (token.type == T_const) {
1644                                 name = "const";
1645                         } else if (token.type == T_volatile) {
1646                                 name = "volatile";
1647                         } else if (token.type == T_cdecl) {
1648                                 /* __attribute__((cdecl)), WITH ms mode */
1649                                 name = "cdecl";
1650                         } else if (token.type == T_IDENTIFIER) {
1651                                 const symbol_t *sym = token.v.symbol;
1652                                 name = sym->string;
1653                         } else {
1654                                 parse_error_expected("while parsing GNU attribute", T_IDENTIFIER, NULL);
1655                                 break;
1656                         }
1657
1658                         next_token();
1659
1660                         int i;
1661                         for (i = 0; i < GNU_AK_LAST; ++i) {
1662                                 if (strcmp_underscore(gnu_attribute_names[i], name) == 0)
1663                                         break;
1664                         }
1665                         gnu_attribute_kind_t kind = (gnu_attribute_kind_t)i;
1666
1667                         attribute = NULL;
1668                         if (kind == GNU_AK_LAST) {
1669                                 if (warning.attribute)
1670                                         warningf(HERE, "'%s' attribute directive ignored", name);
1671
1672                                 /* skip possible arguments */
1673                                 if (token.type == '(') {
1674                                         eat_until_matching_token(')');
1675                                 }
1676                         } else {
1677                                 /* check for arguments */
1678                                 attribute = allocate_gnu_attribute(kind);
1679                                 if (token.type == '(') {
1680                                         next_token();
1681                                         if (token.type == ')') {
1682                                                 /* empty args are allowed */
1683                                                 next_token();
1684                                         } else
1685                                                 attribute->have_arguments = true;
1686                                 }
1687
1688                                 switch (kind) {
1689                                 case GNU_AK_VOLATILE:
1690                                 case GNU_AK_NAKED:
1691                                 case GNU_AK_MALLOC:
1692                                 case GNU_AK_WEAK:
1693                                 case GNU_AK_COMMON:
1694                                 case GNU_AK_NOCOMMON:
1695                                 case GNU_AK_SHARED:
1696                                 case GNU_AK_NOTSHARED:
1697                                 case GNU_AK_NO_INSTRUMENT_FUNCTION:
1698                                 case GNU_AK_WARN_UNUSED_RESULT:
1699                                 case GNU_AK_LONGCALL:
1700                                 case GNU_AK_SHORTCALL:
1701                                 case GNU_AK_LONG_CALL:
1702                                 case GNU_AK_SHORT_CALL:
1703                                 case GNU_AK_FUNCTION_VECTOR:
1704                                 case GNU_AK_INTERRUPT_HANDLER:
1705                                 case GNU_AK_NMI_HANDLER:
1706                                 case GNU_AK_NESTING:
1707                                 case GNU_AK_NEAR:
1708                                 case GNU_AK_FAR:
1709                                 case GNU_AK_SIGNAL:
1710                                 case GNU_AK_EIGTHBIT_DATA:
1711                                 case GNU_AK_TINY_DATA:
1712                                 case GNU_AK_SAVEALL:
1713                                 case GNU_AK_FLATTEN:
1714                                 case GNU_AK_SSEREGPARM:
1715                                 case GNU_AK_EXTERNALLY_VISIBLE:
1716                                 case GNU_AK_RETURN_TWICE:
1717                                 case GNU_AK_MAY_ALIAS:
1718                                 case GNU_AK_MS_STRUCT:
1719                                 case GNU_AK_GCC_STRUCT:
1720                                         goto no_arg;
1721
1722                                 case GNU_AK_CDECL:             modifiers |= DM_CDECL;             goto no_arg;
1723                                 case GNU_AK_FASTCALL:          modifiers |= DM_FASTCALL;          goto no_arg;
1724                                 case GNU_AK_STDCALL:           modifiers |= DM_STDCALL;           goto no_arg;
1725                                 case GNU_AK_UNUSED:            modifiers |= DM_UNUSED;            goto no_arg;
1726                                 case GNU_AK_USED:              modifiers |= DM_USED;              goto no_arg;
1727                                 case GNU_AK_PURE:              modifiers |= DM_PURE;              goto no_arg;
1728                                 case GNU_AK_CONST:             modifiers |= DM_CONST;             goto no_arg;
1729                                 case GNU_AK_ALWAYS_INLINE:     modifiers |= DM_FORCEINLINE;       goto no_arg;
1730                                 case GNU_AK_DLLIMPORT:         modifiers |= DM_DLLIMPORT;         goto no_arg;
1731                                 case GNU_AK_DLLEXPORT:         modifiers |= DM_DLLEXPORT;         goto no_arg;
1732                                 case GNU_AK_PACKED:            modifiers |= DM_PACKED;            goto no_arg;
1733                                 case GNU_AK_NOINLINE:          modifiers |= DM_NOINLINE;          goto no_arg;
1734                                 case GNU_AK_NORETURN:          modifiers |= DM_NORETURN;          goto no_arg;
1735                                 case GNU_AK_NOTHROW:           modifiers |= DM_NOTHROW;           goto no_arg;
1736                                 case GNU_AK_TRANSPARENT_UNION: modifiers |= DM_TRANSPARENT_UNION; goto no_arg;
1737                                 case GNU_AK_CONSTRUCTOR:       modifiers |= DM_CONSTRUCTOR;       goto no_arg;
1738                                 case GNU_AK_DESTRUCTOR:        modifiers |= DM_DESTRUCTOR;        goto no_arg;
1739                                 case GNU_AK_DEPRECATED:        modifiers |= DM_DEPRECATED;        goto no_arg;
1740
1741                                 case GNU_AK_ALIGNED:
1742                                         /* __align__ may be used without an argument */
1743                                         if (attribute->have_arguments) {
1744                                                 parse_gnu_attribute_const_arg(attribute);
1745                                         }
1746                                         break;
1747
1748                                 case GNU_AK_FORMAT_ARG:
1749                                 case GNU_AK_REGPARM:
1750                                 case GNU_AK_TRAP_EXIT:
1751                                         if (!attribute->have_arguments) {
1752                                                 /* should have arguments */
1753                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1754                                                 attribute->invalid = true;
1755                                         } else
1756                                                 parse_gnu_attribute_const_arg(attribute);
1757                                         break;
1758                                 case GNU_AK_ALIAS:
1759                                 case GNU_AK_SECTION:
1760                                 case GNU_AK_SP_SWITCH:
1761                                         if (!attribute->have_arguments) {
1762                                                 /* should have arguments */
1763                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1764                                                 attribute->invalid = true;
1765                                         } else
1766                                                 parse_gnu_attribute_string_arg(attribute, &attribute->u.string);
1767                                         break;
1768                                 case GNU_AK_FORMAT:
1769                                         if (!attribute->have_arguments) {
1770                                                 /* should have arguments */
1771                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1772                                                 attribute->invalid = true;
1773                                         } else
1774                                                 parse_gnu_attribute_format_args(attribute);
1775                                         break;
1776                                 case GNU_AK_WEAKREF:
1777                                         /* may have one string argument */
1778                                         if (attribute->have_arguments)
1779                                                 parse_gnu_attribute_string_arg(attribute, &attribute->u.string);
1780                                         break;
1781                                 case GNU_AK_NONNULL:
1782                                         if (attribute->have_arguments)
1783                                                 parse_gnu_attribute_const_arg_list(attribute);
1784                                         break;
1785                                 case GNU_AK_TLS_MODEL:
1786                                         if (!attribute->have_arguments) {
1787                                                 /* should have arguments */
1788                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1789                                         } else
1790                                                 parse_gnu_attribute_tls_model_arg(attribute);
1791                                         break;
1792                                 case GNU_AK_VISIBILITY:
1793                                         if (!attribute->have_arguments) {
1794                                                 /* should have arguments */
1795                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1796                                         } else
1797                                                 parse_gnu_attribute_visibility_arg(attribute);
1798                                         break;
1799                                 case GNU_AK_MODEL:
1800                                         if (!attribute->have_arguments) {
1801                                                 /* should have arguments */
1802                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1803                                         } else {
1804                                                 parse_gnu_attribute_model_arg(attribute);
1805                                         }
1806                                         break;
1807                                 case GNU_AK_MODE:
1808                                         if (!attribute->have_arguments) {
1809                                                 /* should have arguments */
1810                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1811                                         } else {
1812                                                 parse_gnu_attribute_mode_arg(attribute);
1813                                         }
1814                                         break;
1815                                 case GNU_AK_INTERRUPT:
1816                                         /* may have one string argument */
1817                                         if (attribute->have_arguments)
1818                                                 parse_gnu_attribute_interrupt_arg(attribute);
1819                                         break;
1820                                 case GNU_AK_SENTINEL:
1821                                         /* may have one string argument */
1822                                         if (attribute->have_arguments)
1823                                                 parse_gnu_attribute_const_arg(attribute);
1824                                         break;
1825                                 case GNU_AK_LAST:
1826                                         /* already handled */
1827                                         break;
1828
1829 no_arg:
1830                                         check_no_argument(attribute, name);
1831                                 }
1832                         }
1833                         if (attribute != NULL) {
1834                                 if (last != NULL) {
1835                                         last->next = attribute;
1836                                         last       = attribute;
1837                                 } else {
1838                                         head = last = attribute;
1839                                 }
1840                         }
1841
1842                         if (token.type != ',')
1843                                 break;
1844                         next_token();
1845                 }
1846         }
1847         expect(')');
1848         expect(')');
1849 end_error:
1850         *attributes = head;
1851
1852         return modifiers;
1853 }
1854
1855 /**
1856  * Parse GNU attributes.
1857  */
1858 static decl_modifiers_t parse_attributes(gnu_attribute_t **attributes)
1859 {
1860         decl_modifiers_t modifiers = 0;
1861
1862         while (true) {
1863                 switch (token.type) {
1864                 case T___attribute__:
1865                         modifiers |= parse_gnu_attribute(attributes);
1866                         continue;
1867
1868                 case T_asm:
1869                         next_token();
1870                         expect('(');
1871                         if (token.type != T_STRING_LITERAL) {
1872                                 parse_error_expected("while parsing assembler attribute",
1873                                                      T_STRING_LITERAL, NULL);
1874                                 eat_until_matching_token('(');
1875                                 break;
1876                         } else {
1877                                 parse_string_literals();
1878                         }
1879                         expect(')');
1880                         continue;
1881
1882                 case T_cdecl:     modifiers |= DM_CDECL;    break;
1883                 case T__fastcall: modifiers |= DM_FASTCALL; break;
1884                 case T__stdcall:  modifiers |= DM_STDCALL;  break;
1885
1886                 case T___thiscall:
1887                         /* TODO record modifier */
1888                         if (warning.other)
1889                                 warningf(HERE, "Ignoring declaration modifier %K", &token);
1890                         break;
1891
1892 end_error:
1893                 default: return modifiers;
1894                 }
1895
1896                 next_token();
1897         }
1898 }
1899
1900 static void mark_vars_read(expression_t *expr, variable_t *lhs_var);
1901
1902 static variable_t *determine_lhs_var(expression_t *const expr,
1903                                      variable_t *lhs_var)
1904 {
1905         switch (expr->kind) {
1906                 case EXPR_REFERENCE: {
1907                         entity_t *const entity = expr->reference.entity;
1908                         /* we should only find variables as lavlues... */
1909                         if (entity->base.kind != ENTITY_VARIABLE)
1910                                 return NULL;
1911
1912                         return &entity->variable;
1913                 }
1914
1915                 case EXPR_ARRAY_ACCESS: {
1916                         expression_t  *const ref = expr->array_access.array_ref;
1917                         variable_t    *      var = NULL;
1918                         if (is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1919                                 var     = determine_lhs_var(ref, lhs_var);
1920                                 lhs_var = var;
1921                         } else {
1922                                 mark_vars_read(expr->select.compound, lhs_var);
1923                         }
1924                         mark_vars_read(expr->array_access.index, lhs_var);
1925                         return var;
1926                 }
1927
1928                 case EXPR_SELECT: {
1929                         if (is_type_compound(skip_typeref(expr->base.type))) {
1930                                 return determine_lhs_var(expr->select.compound, lhs_var);
1931                         } else {
1932                                 mark_vars_read(expr->select.compound, lhs_var);
1933                                 return NULL;
1934                         }
1935                 }
1936
1937                 case EXPR_UNARY_DEREFERENCE: {
1938                         expression_t *const val = expr->unary.value;
1939                         if (val->kind == EXPR_UNARY_TAKE_ADDRESS) {
1940                                 /* *&x is a NOP */
1941                                 return determine_lhs_var(val->unary.value, lhs_var);
1942                         } else {
1943                                 mark_vars_read(val, NULL);
1944                                 return NULL;
1945                         }
1946                 }
1947
1948                 default:
1949                         mark_vars_read(expr, NULL);
1950                         return NULL;
1951         }
1952 }
1953
1954 #define VAR_ANY ((variable_t*)-1)
1955
1956 /**
1957  * Mark declarations, which are read.  This is used to deted variables, which
1958  * are never read.
1959  * Example:
1960  * x = x + 1;
1961  *   x is not marked as "read", because it is only read to calculate its own new
1962  *   value.
1963  *
1964  * x += y; y += x;
1965  *   x and y are not detected as "not read", because multiple variables are
1966  *   involved.
1967  */
1968 static void mark_vars_read(expression_t *const expr, variable_t *lhs_var)
1969 {
1970         switch (expr->kind) {
1971                 case EXPR_REFERENCE: {
1972                         entity_t *const entity = expr->reference.entity;
1973                         if (entity->kind != ENTITY_VARIABLE)
1974                                 return;
1975
1976                         variable_t *variable = &entity->variable;
1977                         if (lhs_var != variable && lhs_var != VAR_ANY) {
1978                                 variable->read = true;
1979                         }
1980                         return;
1981                 }
1982
1983                 case EXPR_CALL:
1984                         // TODO respect pure/const
1985                         mark_vars_read(expr->call.function, NULL);
1986                         for (call_argument_t *arg = expr->call.arguments; arg != NULL; arg = arg->next) {
1987                                 mark_vars_read(arg->expression, NULL);
1988                         }
1989                         return;
1990
1991                 case EXPR_CONDITIONAL:
1992                         // TODO lhs_decl should depend on whether true/false have an effect
1993                         mark_vars_read(expr->conditional.condition, NULL);
1994                         if (expr->conditional.true_expression != NULL)
1995                                 mark_vars_read(expr->conditional.true_expression, lhs_var);
1996                         mark_vars_read(expr->conditional.false_expression, lhs_var);
1997                         return;
1998
1999                 case EXPR_SELECT:
2000                         if (lhs_var == VAR_ANY && !is_type_compound(skip_typeref(expr->base.type)))
2001                                 lhs_var = NULL;
2002                         mark_vars_read(expr->select.compound, lhs_var);
2003                         return;
2004
2005                 case EXPR_ARRAY_ACCESS: {
2006                         expression_t *const ref = expr->array_access.array_ref;
2007                         mark_vars_read(ref, lhs_var);
2008                         lhs_var = determine_lhs_var(ref, lhs_var);
2009                         mark_vars_read(expr->array_access.index, lhs_var);
2010                         return;
2011                 }
2012
2013                 case EXPR_VA_ARG:
2014                         mark_vars_read(expr->va_arge.ap, lhs_var);
2015                         return;
2016
2017                 case EXPR_UNARY_CAST:
2018                         /* Special case: Use void cast to mark a variable as "read" */
2019                         if (is_type_atomic(skip_typeref(expr->base.type), ATOMIC_TYPE_VOID))
2020                                 lhs_var = NULL;
2021                         goto unary;
2022
2023
2024                 case EXPR_UNARY_THROW:
2025                         if (expr->unary.value == NULL)
2026                                 return;
2027                         /* FALLTHROUGH */
2028                 case EXPR_UNARY_DEREFERENCE:
2029                 case EXPR_UNARY_DELETE:
2030                 case EXPR_UNARY_DELETE_ARRAY:
2031                         if (lhs_var == VAR_ANY)
2032                                 lhs_var = NULL;
2033                         goto unary;
2034
2035                 case EXPR_UNARY_NEGATE:
2036                 case EXPR_UNARY_PLUS:
2037                 case EXPR_UNARY_BITWISE_NEGATE:
2038                 case EXPR_UNARY_NOT:
2039                 case EXPR_UNARY_TAKE_ADDRESS:
2040                 case EXPR_UNARY_POSTFIX_INCREMENT:
2041                 case EXPR_UNARY_POSTFIX_DECREMENT:
2042                 case EXPR_UNARY_PREFIX_INCREMENT:
2043                 case EXPR_UNARY_PREFIX_DECREMENT:
2044                 case EXPR_UNARY_CAST_IMPLICIT:
2045                 case EXPR_UNARY_ASSUME:
2046 unary:
2047                         mark_vars_read(expr->unary.value, lhs_var);
2048                         return;
2049
2050                 case EXPR_BINARY_ADD:
2051                 case EXPR_BINARY_SUB:
2052                 case EXPR_BINARY_MUL:
2053                 case EXPR_BINARY_DIV:
2054                 case EXPR_BINARY_MOD:
2055                 case EXPR_BINARY_EQUAL:
2056                 case EXPR_BINARY_NOTEQUAL:
2057                 case EXPR_BINARY_LESS:
2058                 case EXPR_BINARY_LESSEQUAL:
2059                 case EXPR_BINARY_GREATER:
2060                 case EXPR_BINARY_GREATEREQUAL:
2061                 case EXPR_BINARY_BITWISE_AND:
2062                 case EXPR_BINARY_BITWISE_OR:
2063                 case EXPR_BINARY_BITWISE_XOR:
2064                 case EXPR_BINARY_LOGICAL_AND:
2065                 case EXPR_BINARY_LOGICAL_OR:
2066                 case EXPR_BINARY_SHIFTLEFT:
2067                 case EXPR_BINARY_SHIFTRIGHT:
2068                 case EXPR_BINARY_COMMA:
2069                 case EXPR_BINARY_ISGREATER:
2070                 case EXPR_BINARY_ISGREATEREQUAL:
2071                 case EXPR_BINARY_ISLESS:
2072                 case EXPR_BINARY_ISLESSEQUAL:
2073                 case EXPR_BINARY_ISLESSGREATER:
2074                 case EXPR_BINARY_ISUNORDERED:
2075                         mark_vars_read(expr->binary.left,  lhs_var);
2076                         mark_vars_read(expr->binary.right, lhs_var);
2077                         return;
2078
2079                 case EXPR_BINARY_ASSIGN:
2080                 case EXPR_BINARY_MUL_ASSIGN:
2081                 case EXPR_BINARY_DIV_ASSIGN:
2082                 case EXPR_BINARY_MOD_ASSIGN:
2083                 case EXPR_BINARY_ADD_ASSIGN:
2084                 case EXPR_BINARY_SUB_ASSIGN:
2085                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:
2086                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
2087                 case EXPR_BINARY_BITWISE_AND_ASSIGN:
2088                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:
2089                 case EXPR_BINARY_BITWISE_OR_ASSIGN: {
2090                         if (lhs_var == VAR_ANY)
2091                                 lhs_var = NULL;
2092                         lhs_var = determine_lhs_var(expr->binary.left, lhs_var);
2093                         mark_vars_read(expr->binary.right, lhs_var);
2094                         return;
2095                 }
2096
2097                 case EXPR_VA_START:
2098                         determine_lhs_var(expr->va_starte.ap, lhs_var);
2099                         return;
2100
2101                 case EXPR_UNKNOWN:
2102                 case EXPR_INVALID:
2103                 case EXPR_CONST:
2104                 case EXPR_CHARACTER_CONSTANT:
2105                 case EXPR_WIDE_CHARACTER_CONSTANT:
2106                 case EXPR_STRING_LITERAL:
2107                 case EXPR_WIDE_STRING_LITERAL:
2108                 case EXPR_COMPOUND_LITERAL: // TODO init?
2109                 case EXPR_SIZEOF:
2110                 case EXPR_CLASSIFY_TYPE:
2111                 case EXPR_ALIGNOF:
2112                 case EXPR_FUNCNAME:
2113                 case EXPR_BUILTIN_SYMBOL:
2114                 case EXPR_BUILTIN_CONSTANT_P:
2115                 case EXPR_BUILTIN_PREFETCH:
2116                 case EXPR_OFFSETOF:
2117                 case EXPR_STATEMENT: // TODO
2118                 case EXPR_LABEL_ADDRESS:
2119                 case EXPR_BINARY_BUILTIN_EXPECT:
2120                 case EXPR_REFERENCE_ENUM_VALUE:
2121                         return;
2122         }
2123
2124         panic("unhandled expression");
2125 }
2126
2127 static designator_t *parse_designation(void)
2128 {
2129         designator_t *result = NULL;
2130         designator_t *last   = NULL;
2131
2132         while (true) {
2133                 designator_t *designator;
2134                 switch (token.type) {
2135                 case '[':
2136                         designator = allocate_ast_zero(sizeof(designator[0]));
2137                         designator->source_position = token.source_position;
2138                         next_token();
2139                         add_anchor_token(']');
2140                         designator->array_index = parse_constant_expression();
2141                         rem_anchor_token(']');
2142                         expect(']');
2143                         break;
2144                 case '.':
2145                         designator = allocate_ast_zero(sizeof(designator[0]));
2146                         designator->source_position = token.source_position;
2147                         next_token();
2148                         if (token.type != T_IDENTIFIER) {
2149                                 parse_error_expected("while parsing designator",
2150                                                      T_IDENTIFIER, NULL);
2151                                 return NULL;
2152                         }
2153                         designator->symbol = token.v.symbol;
2154                         next_token();
2155                         break;
2156                 default:
2157                         expect('=');
2158                         return result;
2159                 }
2160
2161                 assert(designator != NULL);
2162                 if (last != NULL) {
2163                         last->next = designator;
2164                 } else {
2165                         result = designator;
2166                 }
2167                 last = designator;
2168         }
2169 end_error:
2170         return NULL;
2171 }
2172
2173 static initializer_t *initializer_from_string(array_type_t *type,
2174                                               const string_t *const string)
2175 {
2176         /* TODO: check len vs. size of array type */
2177         (void) type;
2178
2179         initializer_t *initializer = allocate_initializer_zero(INITIALIZER_STRING);
2180         initializer->string.string = *string;
2181
2182         return initializer;
2183 }
2184
2185 static initializer_t *initializer_from_wide_string(array_type_t *const type,
2186                                                    wide_string_t *const string)
2187 {
2188         /* TODO: check len vs. size of array type */
2189         (void) type;
2190
2191         initializer_t *const initializer =
2192                 allocate_initializer_zero(INITIALIZER_WIDE_STRING);
2193         initializer->wide_string.string = *string;
2194
2195         return initializer;
2196 }
2197
2198 /**
2199  * Build an initializer from a given expression.
2200  */
2201 static initializer_t *initializer_from_expression(type_t *orig_type,
2202                                                   expression_t *expression)
2203 {
2204         /* TODO check that expression is a constant expression */
2205
2206         /* § 6.7.8.14/15 char array may be initialized by string literals */
2207         type_t *type           = skip_typeref(orig_type);
2208         type_t *expr_type_orig = expression->base.type;
2209         type_t *expr_type      = skip_typeref(expr_type_orig);
2210         if (is_type_array(type) && expr_type->kind == TYPE_POINTER) {
2211                 array_type_t *const array_type   = &type->array;
2212                 type_t       *const element_type = skip_typeref(array_type->element_type);
2213
2214                 if (element_type->kind == TYPE_ATOMIC) {
2215                         atomic_type_kind_t akind = element_type->atomic.akind;
2216                         switch (expression->kind) {
2217                                 case EXPR_STRING_LITERAL:
2218                                         if (akind == ATOMIC_TYPE_CHAR
2219                                                         || akind == ATOMIC_TYPE_SCHAR
2220                                                         || akind == ATOMIC_TYPE_UCHAR) {
2221                                                 return initializer_from_string(array_type,
2222                                                         &expression->string.value);
2223                                         }
2224
2225                                 case EXPR_WIDE_STRING_LITERAL: {
2226                                         type_t *bare_wchar_type = skip_typeref(type_wchar_t);
2227                                         if (get_unqualified_type(element_type) == bare_wchar_type) {
2228                                                 return initializer_from_wide_string(array_type,
2229                                                         &expression->wide_string.value);
2230                                         }
2231                                 }
2232
2233                                 default:
2234                                         break;
2235                         }
2236                 }
2237         }
2238
2239         assign_error_t error = semantic_assign(type, expression);
2240         if (error == ASSIGN_ERROR_INCOMPATIBLE)
2241                 return NULL;
2242         report_assign_error(error, type, expression, "initializer",
2243                             &expression->base.source_position);
2244
2245         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
2246 #if 0
2247         if (type->kind == TYPE_BITFIELD) {
2248                 type = type->bitfield.base_type;
2249         }
2250 #endif
2251         result->value.value = create_implicit_cast(expression, type);
2252
2253         return result;
2254 }
2255
2256 /**
2257  * Checks if a given expression can be used as an constant initializer.
2258  */
2259 static bool is_initializer_constant(const expression_t *expression)
2260 {
2261         return is_constant_expression(expression)
2262                 || is_address_constant(expression);
2263 }
2264
2265 /**
2266  * Parses an scalar initializer.
2267  *
2268  * § 6.7.8.11; eat {} without warning
2269  */
2270 static initializer_t *parse_scalar_initializer(type_t *type,
2271                                                bool must_be_constant)
2272 {
2273         /* there might be extra {} hierarchies */
2274         int braces = 0;
2275         if (token.type == '{') {
2276                 if (warning.other)
2277                         warningf(HERE, "extra curly braces around scalar initializer");
2278                 do {
2279                         ++braces;
2280                         next_token();
2281                 } while (token.type == '{');
2282         }
2283
2284         expression_t *expression = parse_assignment_expression();
2285         mark_vars_read(expression, NULL);
2286         if (must_be_constant && !is_initializer_constant(expression)) {
2287                 errorf(&expression->base.source_position,
2288                        "Initialisation expression '%E' is not constant\n",
2289                        expression);
2290         }
2291
2292         initializer_t *initializer = initializer_from_expression(type, expression);
2293
2294         if (initializer == NULL) {
2295                 errorf(&expression->base.source_position,
2296                        "expression '%E' (type '%T') doesn't match expected type '%T'",
2297                        expression, expression->base.type, type);
2298                 /* TODO */
2299                 return NULL;
2300         }
2301
2302         bool additional_warning_displayed = false;
2303         while (braces > 0) {
2304                 if (token.type == ',') {
2305                         next_token();
2306                 }
2307                 if (token.type != '}') {
2308                         if (!additional_warning_displayed && warning.other) {
2309                                 warningf(HERE, "additional elements in scalar initializer");
2310                                 additional_warning_displayed = true;
2311                         }
2312                 }
2313                 eat_block();
2314                 braces--;
2315         }
2316
2317         return initializer;
2318 }
2319
2320 /**
2321  * An entry in the type path.
2322  */
2323 typedef struct type_path_entry_t type_path_entry_t;
2324 struct type_path_entry_t {
2325         type_t *type;       /**< the upper top type. restored to path->top_tye if this entry is popped. */
2326         union {
2327                 size_t         index;          /**< For array types: the current index. */
2328                 declaration_t *compound_entry; /**< For compound types: the current declaration. */
2329         } v;
2330 };
2331
2332 /**
2333  * A type path expression a position inside compound or array types.
2334  */
2335 typedef struct type_path_t type_path_t;
2336 struct type_path_t {
2337         type_path_entry_t *path;         /**< An flexible array containing the current path. */
2338         type_t            *top_type;     /**< type of the element the path points */
2339         size_t             max_index;    /**< largest index in outermost array */
2340 };
2341
2342 /**
2343  * Prints a type path for debugging.
2344  */
2345 static __attribute__((unused)) void debug_print_type_path(
2346                 const type_path_t *path)
2347 {
2348         size_t len = ARR_LEN(path->path);
2349
2350         for (size_t i = 0; i < len; ++i) {
2351                 const type_path_entry_t *entry = & path->path[i];
2352
2353                 type_t *type = skip_typeref(entry->type);
2354                 if (is_type_compound(type)) {
2355                         /* in gcc mode structs can have no members */
2356                         if (entry->v.compound_entry == NULL) {
2357                                 assert(i == len-1);
2358                                 continue;
2359                         }
2360                         fprintf(stderr, ".%s",
2361                                 entry->v.compound_entry->base.symbol->string);
2362                 } else if (is_type_array(type)) {
2363                         fprintf(stderr, "[%u]", (unsigned) entry->v.index);
2364                 } else {
2365                         fprintf(stderr, "-INVALID-");
2366                 }
2367         }
2368         if (path->top_type != NULL) {
2369                 fprintf(stderr, "  (");
2370                 print_type(path->top_type);
2371                 fprintf(stderr, ")");
2372         }
2373 }
2374
2375 /**
2376  * Return the top type path entry, ie. in a path
2377  * (type).a.b returns the b.
2378  */
2379 static type_path_entry_t *get_type_path_top(const type_path_t *path)
2380 {
2381         size_t len = ARR_LEN(path->path);
2382         assert(len > 0);
2383         return &path->path[len-1];
2384 }
2385
2386 /**
2387  * Enlarge the type path by an (empty) element.
2388  */
2389 static type_path_entry_t *append_to_type_path(type_path_t *path)
2390 {
2391         size_t len = ARR_LEN(path->path);
2392         ARR_RESIZE(type_path_entry_t, path->path, len+1);
2393
2394         type_path_entry_t *result = & path->path[len];
2395         memset(result, 0, sizeof(result[0]));
2396         return result;
2397 }
2398
2399 /**
2400  * Descending into a sub-type. Enter the scope of the current top_type.
2401  */
2402 static void descend_into_subtype(type_path_t *path)
2403 {
2404         type_t *orig_top_type = path->top_type;
2405         type_t *top_type      = skip_typeref(orig_top_type);
2406
2407         type_path_entry_t *top = append_to_type_path(path);
2408         top->type              = top_type;
2409
2410         if (is_type_compound(top_type)) {
2411                 compound_t *compound  = top_type->compound.compound;
2412                 entity_t   *entry     = compound->members.entities;
2413
2414                 if (entry != NULL) {
2415                         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
2416                         top->v.compound_entry = &entry->declaration;
2417                         path->top_type = entry->declaration.type;
2418                 } else {
2419                         path->top_type = NULL;
2420                 }
2421         } else if (is_type_array(top_type)) {
2422                 top->v.index   = 0;
2423                 path->top_type = top_type->array.element_type;
2424         } else {
2425                 assert(!is_type_valid(top_type));
2426         }
2427 }
2428
2429 /**
2430  * Pop an entry from the given type path, ie. returning from
2431  * (type).a.b to (type).a
2432  */
2433 static void ascend_from_subtype(type_path_t *path)
2434 {
2435         type_path_entry_t *top = get_type_path_top(path);
2436
2437         path->top_type = top->type;
2438
2439         size_t len = ARR_LEN(path->path);
2440         ARR_RESIZE(type_path_entry_t, path->path, len-1);
2441 }
2442
2443 /**
2444  * Pop entries from the given type path until the given
2445  * path level is reached.
2446  */
2447 static void ascend_to(type_path_t *path, size_t top_path_level)
2448 {
2449         size_t len = ARR_LEN(path->path);
2450
2451         while (len > top_path_level) {
2452                 ascend_from_subtype(path);
2453                 len = ARR_LEN(path->path);
2454         }
2455 }
2456
2457 static bool walk_designator(type_path_t *path, const designator_t *designator,
2458                             bool used_in_offsetof)
2459 {
2460         for (; designator != NULL; designator = designator->next) {
2461                 type_path_entry_t *top       = get_type_path_top(path);
2462                 type_t            *orig_type = top->type;
2463
2464                 type_t *type = skip_typeref(orig_type);
2465
2466                 if (designator->symbol != NULL) {
2467                         symbol_t *symbol = designator->symbol;
2468                         if (!is_type_compound(type)) {
2469                                 if (is_type_valid(type)) {
2470                                         errorf(&designator->source_position,
2471                                                "'.%Y' designator used for non-compound type '%T'",
2472                                                symbol, orig_type);
2473                                 }
2474
2475                                 top->type             = type_error_type;
2476                                 top->v.compound_entry = NULL;
2477                                 orig_type             = type_error_type;
2478                         } else {
2479                                 compound_t *compound = type->compound.compound;
2480                                 entity_t   *iter     = compound->members.entities;
2481                                 for (; iter != NULL; iter = iter->base.next) {
2482                                         if (iter->base.symbol == symbol) {
2483                                                 break;
2484                                         }
2485                                 }
2486                                 if (iter == NULL) {
2487                                         errorf(&designator->source_position,
2488                                                "'%T' has no member named '%Y'", orig_type, symbol);
2489                                         goto failed;
2490                                 }
2491                                 assert(iter->kind == ENTITY_COMPOUND_MEMBER);
2492                                 if (used_in_offsetof) {
2493                                         type_t *real_type = skip_typeref(iter->declaration.type);
2494                                         if (real_type->kind == TYPE_BITFIELD) {
2495                                                 errorf(&designator->source_position,
2496                                                        "offsetof designator '%Y' may not specify bitfield",
2497                                                        symbol);
2498                                                 goto failed;
2499                                         }
2500                                 }
2501
2502                                 top->type             = orig_type;
2503                                 top->v.compound_entry = &iter->declaration;
2504                                 orig_type             = iter->declaration.type;
2505                         }
2506                 } else {
2507                         expression_t *array_index = designator->array_index;
2508                         assert(designator->array_index != NULL);
2509
2510                         if (!is_type_array(type)) {
2511                                 if (is_type_valid(type)) {
2512                                         errorf(&designator->source_position,
2513                                                "[%E] designator used for non-array type '%T'",
2514                                                array_index, orig_type);
2515                                 }
2516                                 goto failed;
2517                         }
2518
2519                         long index = fold_constant(array_index);
2520                         if (!used_in_offsetof) {
2521                                 if (index < 0) {
2522                                         errorf(&designator->source_position,
2523                                                "array index [%E] must be positive", array_index);
2524                                 } else if (type->array.size_constant) {
2525                                         long array_size = type->array.size;
2526                                         if (index >= array_size) {
2527                                                 errorf(&designator->source_position,
2528                                                        "designator [%E] (%d) exceeds array size %d",
2529                                                        array_index, index, array_size);
2530                                         }
2531                                 }
2532                         }
2533
2534                         top->type    = orig_type;
2535                         top->v.index = (size_t) index;
2536                         orig_type    = type->array.element_type;
2537                 }
2538                 path->top_type = orig_type;
2539
2540                 if (designator->next != NULL) {
2541                         descend_into_subtype(path);
2542                 }
2543         }
2544         return true;
2545
2546 failed:
2547         return false;
2548 }
2549
2550 static void advance_current_object(type_path_t *path, size_t top_path_level)
2551 {
2552         type_path_entry_t *top = get_type_path_top(path);
2553
2554         type_t *type = skip_typeref(top->type);
2555         if (is_type_union(type)) {
2556                 /* in unions only the first element is initialized */
2557                 top->v.compound_entry = NULL;
2558         } else if (is_type_struct(type)) {
2559                 declaration_t *entry = top->v.compound_entry;
2560
2561                 entity_t *next_entity = entry->base.next;
2562                 if (next_entity != NULL) {
2563                         assert(is_declaration(next_entity));
2564                         entry = &next_entity->declaration;
2565                 } else {
2566                         entry = NULL;
2567                 }
2568
2569                 top->v.compound_entry = entry;
2570                 if (entry != NULL) {
2571                         path->top_type = entry->type;
2572                         return;
2573                 }
2574         } else if (is_type_array(type)) {
2575                 assert(is_type_array(type));
2576
2577                 top->v.index++;
2578
2579                 if (!type->array.size_constant || top->v.index < type->array.size) {
2580                         return;
2581                 }
2582         } else {
2583                 assert(!is_type_valid(type));
2584                 return;
2585         }
2586
2587         /* we're past the last member of the current sub-aggregate, try if we
2588          * can ascend in the type hierarchy and continue with another subobject */
2589         size_t len = ARR_LEN(path->path);
2590
2591         if (len > top_path_level) {
2592                 ascend_from_subtype(path);
2593                 advance_current_object(path, top_path_level);
2594         } else {
2595                 path->top_type = NULL;
2596         }
2597 }
2598
2599 /**
2600  * skip until token is found.
2601  */
2602 static void skip_until(int type)
2603 {
2604         while (token.type != type) {
2605                 if (token.type == T_EOF)
2606                         return;
2607                 next_token();
2608         }
2609 }
2610
2611 /**
2612  * skip any {...} blocks until a closing bracket is reached.
2613  */
2614 static void skip_initializers(void)
2615 {
2616         if (token.type == '{')
2617                 next_token();
2618
2619         while (token.type != '}') {
2620                 if (token.type == T_EOF)
2621                         return;
2622                 if (token.type == '{') {
2623                         eat_block();
2624                         continue;
2625                 }
2626                 next_token();
2627         }
2628 }
2629
2630 static initializer_t *create_empty_initializer(void)
2631 {
2632         static initializer_t empty_initializer
2633                 = { .list = { { INITIALIZER_LIST }, 0 } };
2634         return &empty_initializer;
2635 }
2636
2637 /**
2638  * Parse a part of an initialiser for a struct or union,
2639  */
2640 static initializer_t *parse_sub_initializer(type_path_t *path,
2641                 type_t *outer_type, size_t top_path_level,
2642                 parse_initializer_env_t *env)
2643 {
2644         if (token.type == '}') {
2645                 /* empty initializer */
2646                 return create_empty_initializer();
2647         }
2648
2649         type_t *orig_type = path->top_type;
2650         type_t *type      = NULL;
2651
2652         if (orig_type == NULL) {
2653                 /* We are initializing an empty compound. */
2654         } else {
2655                 type = skip_typeref(orig_type);
2656         }
2657
2658         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
2659
2660         while (true) {
2661                 designator_t *designator = NULL;
2662                 if (token.type == '.' || token.type == '[') {
2663                         designator = parse_designation();
2664                         goto finish_designator;
2665                 } else if (token.type == T_IDENTIFIER && look_ahead(1)->type == ':') {
2666                         /* GNU-style designator ("identifier: value") */
2667                         designator = allocate_ast_zero(sizeof(designator[0]));
2668                         designator->source_position = token.source_position;
2669                         designator->symbol          = token.v.symbol;
2670                         eat(T_IDENTIFIER);
2671                         eat(':');
2672
2673 finish_designator:
2674                         /* reset path to toplevel, evaluate designator from there */
2675                         ascend_to(path, top_path_level);
2676                         if (!walk_designator(path, designator, false)) {
2677                                 /* can't continue after designation error */
2678                                 goto end_error;
2679                         }
2680
2681                         initializer_t *designator_initializer
2682                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
2683                         designator_initializer->designator.designator = designator;
2684                         ARR_APP1(initializer_t*, initializers, designator_initializer);
2685
2686                         orig_type = path->top_type;
2687                         type      = orig_type != NULL ? skip_typeref(orig_type) : NULL;
2688                 }
2689
2690                 initializer_t *sub;
2691
2692                 if (token.type == '{') {
2693                         if (type != NULL && is_type_scalar(type)) {
2694                                 sub = parse_scalar_initializer(type, env->must_be_constant);
2695                         } else {
2696                                 eat('{');
2697                                 if (type == NULL) {
2698                                         if (env->entity != NULL) {
2699                                                 errorf(HERE,
2700                                                      "extra brace group at end of initializer for '%Y'",
2701                                                      env->entity->base.symbol);
2702                                         } else {
2703                                                 errorf(HERE, "extra brace group at end of initializer");
2704                                         }
2705                                 } else
2706                                         descend_into_subtype(path);
2707
2708                                 add_anchor_token('}');
2709                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
2710                                                             env);
2711                                 rem_anchor_token('}');
2712
2713                                 if (type != NULL) {
2714                                         ascend_from_subtype(path);
2715                                         expect('}');
2716                                 } else {
2717                                         expect('}');
2718                                         goto error_parse_next;
2719                                 }
2720                         }
2721                 } else {
2722                         /* must be an expression */
2723                         expression_t *expression = parse_assignment_expression();
2724
2725                         if (env->must_be_constant && !is_initializer_constant(expression)) {
2726                                 errorf(&expression->base.source_position,
2727                                        "Initialisation expression '%E' is not constant\n",
2728                                        expression);
2729                         }
2730
2731                         if (type == NULL) {
2732                                 /* we are already outside, ... */
2733                                 type_t *const outer_type_skip = skip_typeref(outer_type);
2734                                 if (is_type_compound(outer_type_skip) &&
2735                                     !outer_type_skip->compound.compound->complete) {
2736                                         goto error_parse_next;
2737                                 }
2738                                 goto error_excess;
2739                         }
2740
2741                         /* handle { "string" } special case */
2742                         if ((expression->kind == EXPR_STRING_LITERAL
2743                                         || expression->kind == EXPR_WIDE_STRING_LITERAL)
2744                                         && outer_type != NULL) {
2745                                 sub = initializer_from_expression(outer_type, expression);
2746                                 if (sub != NULL) {
2747                                         if (token.type == ',') {
2748                                                 next_token();
2749                                         }
2750                                         if (token.type != '}' && warning.other) {
2751                                                 warningf(HERE, "excessive elements in initializer for type '%T'",
2752                                                                  orig_type);
2753                                         }
2754                                         /* TODO: eat , ... */
2755                                         return sub;
2756                                 }
2757                         }
2758
2759                         /* descend into subtypes until expression matches type */
2760                         while (true) {
2761                                 orig_type = path->top_type;
2762                                 type      = skip_typeref(orig_type);
2763
2764                                 sub = initializer_from_expression(orig_type, expression);
2765                                 if (sub != NULL) {
2766                                         break;
2767                                 }
2768                                 if (!is_type_valid(type)) {
2769                                         goto end_error;
2770                                 }
2771                                 if (is_type_scalar(type)) {
2772                                         errorf(&expression->base.source_position,
2773                                                         "expression '%E' doesn't match expected type '%T'",
2774                                                         expression, orig_type);
2775                                         goto end_error;
2776                                 }
2777
2778                                 descend_into_subtype(path);
2779                         }
2780                 }
2781
2782                 /* update largest index of top array */
2783                 const type_path_entry_t *first      = &path->path[0];
2784                 type_t                  *first_type = first->type;
2785                 first_type                          = skip_typeref(first_type);
2786                 if (is_type_array(first_type)) {
2787                         size_t index = first->v.index;
2788                         if (index > path->max_index)
2789                                 path->max_index = index;
2790                 }
2791
2792                 if (type != NULL) {
2793                         /* append to initializers list */
2794                         ARR_APP1(initializer_t*, initializers, sub);
2795                 } else {
2796 error_excess:
2797                         if (warning.other) {
2798                                 if (env->entity != NULL) {
2799                                         warningf(HERE, "excess elements in struct initializer for '%Y'",
2800                                            env->entity->base.symbol);
2801                                 } else {
2802                                         warningf(HERE, "excess elements in struct initializer");
2803                                 }
2804                         }
2805                 }
2806
2807 error_parse_next:
2808                 if (token.type == '}') {
2809                         break;
2810                 }
2811                 expect(',');
2812                 if (token.type == '}') {
2813                         break;
2814                 }
2815
2816                 if (type != NULL) {
2817                         /* advance to the next declaration if we are not at the end */
2818                         advance_current_object(path, top_path_level);
2819                         orig_type = path->top_type;
2820                         if (orig_type != NULL)
2821                                 type = skip_typeref(orig_type);
2822                         else
2823                                 type = NULL;
2824                 }
2825         }
2826
2827         size_t len  = ARR_LEN(initializers);
2828         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
2829         initializer_t *result = allocate_ast_zero(size);
2830         result->kind          = INITIALIZER_LIST;
2831         result->list.len      = len;
2832         memcpy(&result->list.initializers, initializers,
2833                len * sizeof(initializers[0]));
2834
2835         DEL_ARR_F(initializers);
2836         ascend_to(path, top_path_level+1);
2837
2838         return result;
2839
2840 end_error:
2841         skip_initializers();
2842         DEL_ARR_F(initializers);
2843         ascend_to(path, top_path_level+1);
2844         return NULL;
2845 }
2846
2847 /**
2848  * Parses an initializer. Parsers either a compound literal
2849  * (env->declaration == NULL) or an initializer of a declaration.
2850  */
2851 static initializer_t *parse_initializer(parse_initializer_env_t *env)
2852 {
2853         type_t        *type   = skip_typeref(env->type);
2854         initializer_t *result = NULL;
2855         size_t         max_index;
2856
2857         if (is_type_scalar(type)) {
2858                 result = parse_scalar_initializer(type, env->must_be_constant);
2859         } else if (token.type == '{') {
2860                 eat('{');
2861
2862                 type_path_t path;
2863                 memset(&path, 0, sizeof(path));
2864                 path.top_type = env->type;
2865                 path.path     = NEW_ARR_F(type_path_entry_t, 0);
2866
2867                 descend_into_subtype(&path);
2868
2869                 add_anchor_token('}');
2870                 result = parse_sub_initializer(&path, env->type, 1, env);
2871                 rem_anchor_token('}');
2872
2873                 max_index = path.max_index;
2874                 DEL_ARR_F(path.path);
2875
2876                 expect('}');
2877         } else {
2878                 /* parse_scalar_initializer() also works in this case: we simply
2879                  * have an expression without {} around it */
2880                 result = parse_scalar_initializer(type, env->must_be_constant);
2881         }
2882
2883         /* § 6.7.8 (22) array initializers for arrays with unknown size determine
2884          * the array type size */
2885         if (is_type_array(type) && type->array.size_expression == NULL
2886                         && result != NULL) {
2887                 size_t size;
2888                 switch (result->kind) {
2889                 case INITIALIZER_LIST:
2890                         size = max_index + 1;
2891                         break;
2892
2893                 case INITIALIZER_STRING:
2894                         size = result->string.string.size;
2895                         break;
2896
2897                 case INITIALIZER_WIDE_STRING:
2898                         size = result->wide_string.string.size;
2899                         break;
2900
2901                 case INITIALIZER_DESIGNATOR:
2902                 case INITIALIZER_VALUE:
2903                         /* can happen for parse errors */
2904                         size = 0;
2905                         break;
2906
2907                 default:
2908                         internal_errorf(HERE, "invalid initializer type");
2909                 }
2910
2911                 expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
2912                 cnst->base.type          = type_size_t;
2913                 cnst->conste.v.int_value = size;
2914
2915                 type_t *new_type = duplicate_type(type);
2916
2917                 new_type->array.size_expression   = cnst;
2918                 new_type->array.size_constant     = true;
2919                 new_type->array.has_implicit_size = true;
2920                 new_type->array.size              = size;
2921                 env->type = new_type;
2922         }
2923
2924         return result;
2925 end_error:
2926         return NULL;
2927 }
2928
2929 static void append_entity(scope_t *scope, entity_t *entity)
2930 {
2931         if (scope->last_entity != NULL) {
2932                 scope->last_entity->base.next = entity;
2933         } else {
2934                 scope->entities = entity;
2935         }
2936         scope->last_entity = entity;
2937 }
2938
2939
2940 static compound_t *parse_compound_type_specifier(bool is_struct)
2941 {
2942         gnu_attribute_t  *attributes = NULL;
2943         decl_modifiers_t  modifiers  = 0;
2944         if (is_struct) {
2945                 eat(T_struct);
2946         } else {
2947                 eat(T_union);
2948         }
2949
2950         symbol_t   *symbol   = NULL;
2951         compound_t *compound = NULL;
2952
2953         if (token.type == T___attribute__) {
2954                 modifiers |= parse_attributes(&attributes);
2955         }
2956
2957         if (token.type == T_IDENTIFIER) {
2958                 symbol = token.v.symbol;
2959                 next_token();
2960
2961                 namespace_tag_t const namespc =
2962                         is_struct ? NAMESPACE_STRUCT : NAMESPACE_UNION;
2963                 entity_t *entity = get_entity(symbol, namespc);
2964                 if (entity != NULL) {
2965                         assert(entity->kind == (is_struct ? ENTITY_STRUCT : ENTITY_UNION));
2966                         compound = &entity->compound;
2967                         if (compound->base.parent_scope != current_scope &&
2968                             (token.type == '{' || token.type == ';')) {
2969                                 /* we're in an inner scope and have a definition. Override
2970                                    existing definition in outer scope */
2971                                 compound = NULL;
2972                         } else if (compound->complete && token.type == '{') {
2973                                 assert(symbol != NULL);
2974                                 errorf(HERE, "multiple definitions of '%s %Y' (previous definition %P)",
2975                                        is_struct ? "struct" : "union", symbol,
2976                                        &compound->base.source_position);
2977                                 /* clear members in the hope to avoid further errors */
2978                                 compound->members.entities = NULL;
2979                         }
2980                 }
2981         } else if (token.type != '{') {
2982                 if (is_struct) {
2983                         parse_error_expected("while parsing struct type specifier",
2984                                              T_IDENTIFIER, '{', NULL);
2985                 } else {
2986                         parse_error_expected("while parsing union type specifier",
2987                                              T_IDENTIFIER, '{', NULL);
2988                 }
2989
2990                 return NULL;
2991         }
2992
2993         if (compound == NULL) {
2994                 entity_kind_t  kind   = is_struct ? ENTITY_STRUCT : ENTITY_UNION;
2995                 entity_t      *entity = allocate_entity_zero(kind);
2996                 compound              = &entity->compound;
2997
2998                 compound->base.namespc =
2999                         (is_struct ? NAMESPACE_STRUCT : NAMESPACE_UNION);
3000                 compound->base.source_position = token.source_position;
3001                 compound->base.symbol          = symbol;
3002                 compound->base.parent_scope    = current_scope;
3003                 if (symbol != NULL) {
3004                         environment_push(entity);
3005                 }
3006                 append_entity(current_scope, entity);
3007         }
3008
3009         if (token.type == '{') {
3010                 parse_compound_type_entries(compound);
3011                 modifiers |= parse_attributes(&attributes);
3012
3013                 if (symbol == NULL) {
3014                         assert(anonymous_entity == NULL);
3015                         anonymous_entity = (entity_t*)compound;
3016                 }
3017         }
3018
3019         compound->modifiers |= modifiers;
3020         return compound;
3021 }
3022
3023 static void parse_enum_entries(type_t *const enum_type)
3024 {
3025         eat('{');
3026
3027         if (token.type == '}') {
3028                 errorf(HERE, "empty enum not allowed");
3029                 next_token();
3030                 return;
3031         }
3032
3033         add_anchor_token('}');
3034         do {
3035                 if (token.type != T_IDENTIFIER) {
3036                         parse_error_expected("while parsing enum entry", T_IDENTIFIER, NULL);
3037                         eat_block();
3038                         rem_anchor_token('}');
3039                         return;
3040                 }
3041
3042                 entity_t *entity             = allocate_entity_zero(ENTITY_ENUM_VALUE);
3043                 entity->enum_value.enum_type = enum_type;
3044                 entity->base.symbol          = token.v.symbol;
3045                 entity->base.source_position = token.source_position;
3046                 next_token();
3047
3048                 if (token.type == '=') {
3049                         next_token();
3050                         expression_t *value = parse_constant_expression();
3051
3052                         value = create_implicit_cast(value, enum_type);
3053                         entity->enum_value.value = value;
3054
3055                         /* TODO semantic */
3056                 }
3057
3058                 record_entity(entity, false);
3059
3060                 if (token.type != ',')
3061                         break;
3062                 next_token();
3063         } while (token.type != '}');
3064         rem_anchor_token('}');
3065
3066         expect('}');
3067
3068 end_error:
3069         ;
3070 }
3071
3072 static type_t *parse_enum_specifier(void)
3073 {
3074         gnu_attribute_t *attributes = NULL;
3075         entity_t        *entity;
3076         symbol_t        *symbol;
3077
3078         eat(T_enum);
3079         if (token.type == T_IDENTIFIER) {
3080                 symbol = token.v.symbol;
3081                 next_token();
3082
3083                 entity = get_entity(symbol, NAMESPACE_ENUM);
3084                 assert(entity == NULL || entity->kind == ENTITY_ENUM);
3085         } else if (token.type != '{') {
3086                 parse_error_expected("while parsing enum type specifier",
3087                                      T_IDENTIFIER, '{', NULL);
3088                 return NULL;
3089         } else {
3090                 entity  = NULL;
3091                 symbol  = NULL;
3092         }
3093
3094         if (entity == NULL) {
3095                 entity                       = allocate_entity_zero(ENTITY_ENUM);
3096                 entity->base.namespc         = NAMESPACE_ENUM;
3097                 entity->base.source_position = token.source_position;
3098                 entity->base.symbol          = symbol;
3099                 entity->base.parent_scope    = current_scope;
3100         }
3101
3102         type_t *const type = allocate_type_zero(TYPE_ENUM);
3103         type->enumt.enume  = &entity->enume;
3104
3105         if (token.type == '{') {
3106                 if (entity->enume.complete) {
3107                         errorf(HERE, "multiple definitions of enum %Y (previous definition %P)",
3108                                symbol, &entity->base.source_position);
3109                 }
3110                 if (symbol != NULL) {
3111                         environment_push(entity);
3112                 }
3113                 append_entity(current_scope, entity);
3114                 entity->enume.complete = true;
3115
3116                 parse_enum_entries(type);
3117                 parse_attributes(&attributes);
3118
3119                 if (symbol == NULL) {
3120                         assert(anonymous_entity == NULL);
3121                         anonymous_entity = entity;
3122                 }
3123         } else if (!entity->enume.complete && !(c_mode & _GNUC)) {
3124                 errorf(HERE, "enum %Y used before definition (incomplete enumes are a GNU extension)",
3125                        symbol);
3126         }
3127
3128         return type;
3129 }
3130
3131 /**
3132  * if a symbol is a typedef to another type, return true
3133  */
3134 static bool is_typedef_symbol(symbol_t *symbol)
3135 {
3136         const entity_t *const entity = get_entity(symbol, NAMESPACE_NORMAL);
3137         return entity != NULL && entity->kind == ENTITY_TYPEDEF;
3138 }
3139
3140 static type_t *parse_typeof(void)
3141 {
3142         eat(T___typeof__);
3143
3144         type_t *type;
3145
3146         expect('(');
3147         add_anchor_token(')');
3148
3149         expression_t *expression  = NULL;
3150
3151         bool old_type_prop     = in_type_prop;
3152         bool old_gcc_extension = in_gcc_extension;
3153         in_type_prop           = true;
3154
3155         while (token.type == T___extension__) {
3156                 /* This can be a prefix to a typename or an expression. */
3157                 next_token();
3158                 in_gcc_extension = true;
3159         }
3160         switch (token.type) {
3161         case T_IDENTIFIER:
3162                 if (is_typedef_symbol(token.v.symbol)) {
3163                         type = parse_typename();
3164                 } else {
3165                         expression = parse_expression();
3166                         type       = expression->base.type;
3167                 }
3168                 break;
3169
3170         TYPENAME_START
3171                 type = parse_typename();
3172                 break;
3173
3174         default:
3175                 expression = parse_expression();
3176                 type       = expression->base.type;
3177                 break;
3178         }
3179         in_type_prop     = old_type_prop;
3180         in_gcc_extension = old_gcc_extension;
3181
3182         rem_anchor_token(')');
3183         expect(')');
3184
3185         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
3186         typeof_type->typeoft.expression  = expression;
3187         typeof_type->typeoft.typeof_type = type;
3188
3189         return typeof_type;
3190 end_error:
3191         return NULL;
3192 }
3193
3194 typedef enum specifiers_t {
3195         SPECIFIER_SIGNED    = 1 << 0,
3196         SPECIFIER_UNSIGNED  = 1 << 1,
3197         SPECIFIER_LONG      = 1 << 2,
3198         SPECIFIER_INT       = 1 << 3,
3199         SPECIFIER_DOUBLE    = 1 << 4,
3200         SPECIFIER_CHAR      = 1 << 5,
3201         SPECIFIER_SHORT     = 1 << 6,
3202         SPECIFIER_LONG_LONG = 1 << 7,
3203         SPECIFIER_FLOAT     = 1 << 8,
3204         SPECIFIER_BOOL      = 1 << 9,
3205         SPECIFIER_VOID      = 1 << 10,
3206         SPECIFIER_INT8      = 1 << 11,
3207         SPECIFIER_INT16     = 1 << 12,
3208         SPECIFIER_INT32     = 1 << 13,
3209         SPECIFIER_INT64     = 1 << 14,
3210         SPECIFIER_INT128    = 1 << 15,
3211         SPECIFIER_COMPLEX   = 1 << 16,
3212         SPECIFIER_IMAGINARY = 1 << 17,
3213 } specifiers_t;
3214
3215 static type_t *create_builtin_type(symbol_t *const symbol,
3216                                    type_t *const real_type)
3217 {
3218         type_t *type            = allocate_type_zero(TYPE_BUILTIN);
3219         type->builtin.symbol    = symbol;
3220         type->builtin.real_type = real_type;
3221
3222         type_t *result = typehash_insert(type);
3223         if (type != result) {
3224                 free_type(type);
3225         }
3226
3227         return result;
3228 }
3229
3230 static type_t *get_typedef_type(symbol_t *symbol)
3231 {
3232         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
3233         if (entity == NULL || entity->kind != ENTITY_TYPEDEF)
3234                 return NULL;
3235
3236         type_t *type            = allocate_type_zero(TYPE_TYPEDEF);
3237         type->typedeft.typedefe = &entity->typedefe;
3238
3239         return type;
3240 }
3241
3242 /**
3243  * check for the allowed MS alignment values.
3244  */
3245 static bool check_alignment_value(long long intvalue)
3246 {
3247         if (intvalue < 1 || intvalue > 8192) {
3248                 errorf(HERE, "illegal alignment value");
3249                 return false;
3250         }
3251         unsigned v = (unsigned)intvalue;
3252         for (unsigned i = 1; i <= 8192; i += i) {
3253                 if (i == v)
3254                         return true;
3255         }
3256         errorf(HERE, "alignment must be power of two");
3257         return false;
3258 }
3259
3260 #define DET_MOD(name, tag) do { \
3261         if (*modifiers & tag && warning.other) warningf(HERE, #name " used more than once"); \
3262         *modifiers |= tag; \
3263 } while (0)
3264
3265 static void parse_microsoft_extended_decl_modifier(declaration_specifiers_t *specifiers)
3266 {
3267         decl_modifiers_t *modifiers = &specifiers->modifiers;
3268
3269         while (true) {
3270                 if (token.type == T_restrict) {
3271                         next_token();
3272                         DET_MOD(restrict, DM_RESTRICT);
3273                         goto end_loop;
3274                 } else if (token.type != T_IDENTIFIER)
3275                         break;
3276                 symbol_t *symbol = token.v.symbol;
3277                 if (symbol == sym_align) {
3278                         next_token();
3279                         expect('(');
3280                         if (token.type != T_INTEGER)
3281                                 goto end_error;
3282                         if (check_alignment_value(token.v.intvalue)) {
3283                                 if (specifiers->alignment != 0 && warning.other)
3284                                         warningf(HERE, "align used more than once");
3285                                 specifiers->alignment = (unsigned char)token.v.intvalue;
3286                         }
3287                         next_token();
3288                         expect(')');
3289                 } else if (symbol == sym_allocate) {
3290                         next_token();
3291                         expect('(');
3292                         if (token.type != T_IDENTIFIER)
3293                                 goto end_error;
3294                         (void)token.v.symbol;
3295                         expect(')');
3296                 } else if (symbol == sym_dllimport) {
3297                         next_token();
3298                         DET_MOD(dllimport, DM_DLLIMPORT);
3299                 } else if (symbol == sym_dllexport) {
3300                         next_token();
3301                         DET_MOD(dllexport, DM_DLLEXPORT);
3302                 } else if (symbol == sym_thread) {
3303                         next_token();
3304                         DET_MOD(thread, DM_THREAD);
3305                 } else if (symbol == sym_naked) {
3306                         next_token();
3307                         DET_MOD(naked, DM_NAKED);
3308                 } else if (symbol == sym_noinline) {
3309                         next_token();
3310                         DET_MOD(noinline, DM_NOINLINE);
3311                 } else if (symbol == sym_noreturn) {
3312                         next_token();
3313                         DET_MOD(noreturn, DM_NORETURN);
3314                 } else if (symbol == sym_nothrow) {
3315                         next_token();
3316                         DET_MOD(nothrow, DM_NOTHROW);
3317                 } else if (symbol == sym_novtable) {
3318                         next_token();
3319                         DET_MOD(novtable, DM_NOVTABLE);
3320                 } else if (symbol == sym_property) {
3321                         next_token();
3322                         expect('(');
3323                         for (;;) {
3324                                 bool is_get = false;
3325                                 if (token.type != T_IDENTIFIER)
3326                                         goto end_error;
3327                                 if (token.v.symbol == sym_get) {
3328                                         is_get = true;
3329                                 } else if (token.v.symbol == sym_put) {
3330                                 } else {
3331                                         errorf(HERE, "Bad property name '%Y'", token.v.symbol);
3332                                         goto end_error;
3333                                 }
3334                                 next_token();
3335                                 expect('=');
3336                                 if (token.type != T_IDENTIFIER)
3337                                         goto end_error;
3338                                 if (is_get) {
3339                                         if (specifiers->get_property_sym != NULL) {
3340                                                 errorf(HERE, "get property name already specified");
3341                                         } else {
3342                                                 specifiers->get_property_sym = token.v.symbol;
3343                                         }
3344                                 } else {
3345                                         if (specifiers->put_property_sym != NULL) {
3346                                                 errorf(HERE, "put property name already specified");
3347                                         } else {
3348                                                 specifiers->put_property_sym = token.v.symbol;
3349                                         }
3350                                 }
3351                                 next_token();
3352                                 if (token.type == ',') {
3353                                         next_token();
3354                                         continue;
3355                                 }
3356                                 break;
3357                         }
3358                         expect(')');
3359                 } else if (symbol == sym_selectany) {
3360                         next_token();
3361                         DET_MOD(selectany, DM_SELECTANY);
3362                 } else if (symbol == sym_uuid) {
3363                         next_token();
3364                         expect('(');
3365                         if (token.type != T_STRING_LITERAL)
3366                                 goto end_error;
3367                         next_token();
3368                         expect(')');
3369                 } else if (symbol == sym_deprecated) {
3370                         next_token();
3371                         if (specifiers->deprecated != 0 && warning.other)
3372                                 warningf(HERE, "deprecated used more than once");
3373                         specifiers->deprecated = true;
3374                         if (token.type == '(') {
3375                                 next_token();
3376                                 if (token.type == T_STRING_LITERAL) {
3377                                         specifiers->deprecated_string = token.v.string.begin;
3378                                         next_token();
3379                                 } else {
3380                                         errorf(HERE, "string literal expected");
3381                                 }
3382                                 expect(')');
3383                         }
3384                 } else if (symbol == sym_noalias) {
3385                         next_token();
3386                         DET_MOD(noalias, DM_NOALIAS);
3387                 } else {
3388                         if (warning.other)
3389                                 warningf(HERE, "Unknown modifier %Y ignored", token.v.symbol);
3390                         next_token();
3391                         if (token.type == '(')
3392                                 skip_until(')');
3393                 }
3394 end_loop:
3395                 if (token.type == ',')
3396                         next_token();
3397         }
3398 end_error:
3399         return;
3400 }
3401
3402 static entity_t *create_error_entity(symbol_t *symbol, entity_kind_tag_t kind)
3403 {
3404         entity_t *entity             = allocate_entity_zero(kind);
3405         entity->base.source_position = *HERE;
3406         entity->base.symbol          = symbol;
3407         if (is_declaration(entity)) {
3408                 entity->declaration.type     = type_error_type;
3409                 entity->declaration.implicit = true;
3410         } else if (kind == ENTITY_TYPEDEF) {
3411                 entity->typedefe.type = type_error_type;
3412         }
3413         record_entity(entity, false);
3414         return entity;
3415 }
3416
3417 static void parse_microsoft_based(declaration_specifiers_t *specifiers)
3418 {
3419         if (token.type != T_IDENTIFIER) {
3420                 parse_error_expected("while parsing __based", T_IDENTIFIER, NULL);
3421                 return;
3422         }
3423         symbol_t *symbol = token.v.symbol;
3424         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
3425
3426         if (entity == NULL || entity->base.kind != ENTITY_VARIABLE) {
3427                 errorf(HERE, "'%Y' is not a variable name.", symbol);
3428                 entity = create_error_entity(symbol, ENTITY_VARIABLE);
3429         } else {
3430                 variable_t *variable = &entity->variable;
3431
3432                 if (specifiers->based_variable != NULL) {
3433                         errorf(HERE, "__based type qualifier specified more than once");
3434                 }
3435                 specifiers->based_variable = variable;
3436
3437                 type_t *const type = variable->base.type;
3438
3439                 if (is_type_valid(type)) {
3440                         if (! is_type_pointer(skip_typeref(type))) {
3441                                 errorf(HERE, "variable in __based modifier must have pointer type instead of %T", type);
3442                         }
3443                         if (variable->base.base.parent_scope != file_scope) {
3444                                 errorf(HERE, "a nonstatic local variable may not be used in a __based specification");
3445                         }
3446                 }
3447         }
3448         next_token();
3449 }
3450
3451 /**
3452  * Finish the construction of a struct type by calculating
3453  * its size, offsets, alignment.
3454  */
3455 static void finish_struct_type(compound_type_t *type)
3456 {
3457         assert(type->compound != NULL);
3458
3459         compound_t *compound = type->compound;
3460         if (!compound->complete)
3461                 return;
3462
3463         il_size_t      size           = 0;
3464         il_size_t      offset;
3465         il_alignment_t alignment      = 1;
3466         bool           need_pad       = false;
3467
3468         entity_t *entry = compound->members.entities;
3469         for (; entry != NULL; entry = entry->base.next) {
3470                 if (entry->kind != ENTITY_COMPOUND_MEMBER)
3471                         continue;
3472
3473                 type_t *m_type = skip_typeref(entry->declaration.type);
3474                 if (! is_type_valid(m_type)) {
3475                         /* simply ignore errors here */
3476                         continue;
3477                 }
3478                 il_alignment_t m_alignment = m_type->base.alignment;
3479                 if (m_alignment > alignment)
3480                         alignment = m_alignment;
3481
3482                 offset = (size + m_alignment - 1) & -m_alignment;
3483
3484                 if (offset > size)
3485                         need_pad = true;
3486                 entry->compound_member.offset = offset;
3487                 size = offset + m_type->base.size;
3488         }
3489         if (type->base.alignment != 0) {
3490                 alignment = type->base.alignment;
3491         }
3492
3493         offset = (size + alignment - 1) & -alignment;
3494         if (offset > size)
3495                 need_pad = true;
3496
3497         if (warning.padded && need_pad) {
3498                 warningf(&compound->base.source_position,
3499                         "'%#T' needs padding", type, compound->base.symbol);
3500         }
3501         if (warning.packed && !need_pad) {
3502                 warningf(&compound->base.source_position,
3503                         "superfluous packed attribute on '%#T'",
3504                         type, compound->base.symbol);
3505         }
3506
3507         type->base.size      = offset;
3508         type->base.alignment = alignment;
3509 }
3510
3511 /**
3512  * Finish the construction of an union type by calculating
3513  * its size and alignment.
3514  */
3515 static void finish_union_type(compound_type_t *type)
3516 {
3517         assert(type->compound != NULL);
3518
3519         compound_t *compound = type->compound;
3520         if (! compound->complete)
3521                 return;
3522
3523         il_size_t      size      = 0;
3524         il_alignment_t alignment = 1;
3525
3526         entity_t *entry = compound->members.entities;
3527         for (; entry != NULL; entry = entry->base.next) {
3528                 if (entry->kind != ENTITY_COMPOUND_MEMBER)
3529                         continue;
3530
3531                 type_t *m_type = skip_typeref(entry->declaration.type);
3532                 if (! is_type_valid(m_type))
3533                         continue;
3534
3535                 entry->compound_member.offset = 0;
3536                 if (m_type->base.size > size)
3537                         size = m_type->base.size;
3538                 if (m_type->base.alignment > alignment)
3539                         alignment = m_type->base.alignment;
3540         }
3541         if (type->base.alignment != 0) {
3542                 alignment = type->base.alignment;
3543         }
3544         size = (size + alignment - 1) & -alignment;
3545         type->base.size      = size;
3546         type->base.alignment = alignment;
3547 }
3548
3549 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
3550 {
3551         type_t            *type              = NULL;
3552         type_qualifiers_t  qualifiers        = TYPE_QUALIFIER_NONE;
3553         type_modifiers_t   modifiers         = TYPE_MODIFIER_NONE;
3554         unsigned           type_specifiers   = 0;
3555         bool               newtype           = false;
3556         bool               saw_error         = false;
3557         bool               old_gcc_extension = in_gcc_extension;
3558
3559         specifiers->source_position = token.source_position;
3560
3561         while (true) {
3562                 specifiers->modifiers
3563                         |= parse_attributes(&specifiers->gnu_attributes);
3564                 if (specifiers->modifiers & DM_TRANSPARENT_UNION)
3565                         modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
3566
3567                 switch (token.type) {
3568
3569                 /* storage class */
3570 #define MATCH_STORAGE_CLASS(token, class)                                  \
3571                 case token:                                                        \
3572                         if (specifiers->storage_class != STORAGE_CLASS_NONE) {         \
3573                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
3574                         }                                                              \
3575                         specifiers->storage_class = class;                             \
3576                         next_token();                                                  \
3577                         break;
3578
3579                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
3580                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
3581                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
3582                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
3583                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
3584
3585                 case T__declspec:
3586                         next_token();
3587                         expect('(');
3588                         add_anchor_token(')');
3589                         parse_microsoft_extended_decl_modifier(specifiers);
3590                         rem_anchor_token(')');
3591                         expect(')');
3592                         break;
3593
3594                 case T__based:
3595                         next_token();
3596                         expect('(');
3597                         add_anchor_token(')');
3598                         parse_microsoft_based(specifiers);
3599                         rem_anchor_token(')');
3600                         expect(')');
3601                         break;
3602
3603                 case T___thread:
3604                         switch (specifiers->storage_class) {
3605                         case STORAGE_CLASS_NONE:
3606                                 specifiers->storage_class = STORAGE_CLASS_THREAD;
3607                                 break;
3608
3609                         case STORAGE_CLASS_EXTERN:
3610                                 specifiers->storage_class = STORAGE_CLASS_THREAD_EXTERN;
3611                                 break;
3612
3613                         case STORAGE_CLASS_STATIC:
3614                                 specifiers->storage_class = STORAGE_CLASS_THREAD_STATIC;
3615                                 break;
3616
3617                         default:
3618                                 errorf(HERE, "multiple storage classes in declaration specifiers");
3619                                 break;
3620                         }
3621                         next_token();
3622                         break;
3623
3624                 /* type qualifiers */
3625 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
3626                 case token:                                                     \
3627                         qualifiers |= qualifier;                                    \
3628                         next_token();                                               \
3629                         break
3630
3631                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3632                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3633                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3634                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3635                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3636                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3637                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3638                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3639
3640                 case T___extension__:
3641                         next_token();
3642                         in_gcc_extension = true;
3643                         break;
3644
3645                 /* type specifiers */
3646 #define MATCH_SPECIFIER(token, specifier, name)                         \
3647                 case token:                                                     \
3648                         if (type_specifiers & specifier) {                           \
3649                                 errorf(HERE, "multiple " name " type specifiers given"); \
3650                         } else {                                                    \
3651                                 type_specifiers |= specifier;                           \
3652                         }                                                           \
3653                         next_token();                                               \
3654                         break
3655
3656                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool");
3657                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex");
3658                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary");
3659                 MATCH_SPECIFIER(T__int128,    SPECIFIER_INT128,    "_int128");
3660                 MATCH_SPECIFIER(T__int16,     SPECIFIER_INT16,     "_int16");
3661                 MATCH_SPECIFIER(T__int32,     SPECIFIER_INT32,     "_int32");
3662                 MATCH_SPECIFIER(T__int64,     SPECIFIER_INT64,     "_int64");
3663                 MATCH_SPECIFIER(T__int8,      SPECIFIER_INT8,      "_int8");
3664                 MATCH_SPECIFIER(T_bool,       SPECIFIER_BOOL,      "bool");
3665                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char");
3666                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double");
3667                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float");
3668                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int");
3669                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short");
3670                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed");
3671                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned");
3672                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void");
3673
3674                 case T__forceinline:
3675                         /* only in microsoft mode */
3676                         specifiers->modifiers |= DM_FORCEINLINE;
3677                         /* FALLTHROUGH */
3678
3679                 case T_inline:
3680                         next_token();
3681                         specifiers->is_inline = true;
3682                         break;
3683
3684                 case T_long:
3685                         if (type_specifiers & SPECIFIER_LONG_LONG) {
3686                                 errorf(HERE, "multiple type specifiers given");
3687                         } else if (type_specifiers & SPECIFIER_LONG) {
3688                                 type_specifiers |= SPECIFIER_LONG_LONG;
3689                         } else {
3690                                 type_specifiers |= SPECIFIER_LONG;
3691                         }
3692                         next_token();
3693                         break;
3694
3695                 case T_struct: {
3696                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
3697
3698                         type->compound.compound = parse_compound_type_specifier(true);
3699                         finish_struct_type(&type->compound);
3700                         break;
3701                 }
3702                 case T_union: {
3703                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
3704                         type->compound.compound = parse_compound_type_specifier(false);
3705                         if (type->compound.compound->modifiers & DM_TRANSPARENT_UNION)
3706                                 modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
3707                         finish_union_type(&type->compound);
3708                         break;
3709                 }
3710                 case T_enum:
3711                         type = parse_enum_specifier();
3712                         break;
3713                 case T___typeof__:
3714                         type = parse_typeof();
3715                         break;
3716                 case T___builtin_va_list:
3717                         type = duplicate_type(type_valist);
3718                         next_token();
3719                         break;
3720
3721                 case T_IDENTIFIER: {
3722                         /* only parse identifier if we haven't found a type yet */
3723                         if (type != NULL || type_specifiers != 0) {
3724                                 /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
3725                                  * declaration, so it doesn't generate errors about expecting '(' or
3726                                  * '{' later on. */
3727                                 switch (look_ahead(1)->type) {
3728                                         STORAGE_CLASSES
3729                                         TYPE_SPECIFIERS
3730                                         case T_const:
3731                                         case T_restrict:
3732                                         case T_volatile:
3733                                         case T_inline:
3734                                         case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
3735                                         case T_IDENTIFIER:
3736                                         case '*':
3737                                                 errorf(HERE, "discarding stray %K in declaration specifier", &token);
3738                                                 next_token();
3739                                                 continue;
3740
3741                                         default:
3742                                                 goto finish_specifiers;
3743                                 }
3744                         }
3745
3746                         type_t *const typedef_type = get_typedef_type(token.v.symbol);
3747                         if (typedef_type == NULL) {
3748                                 /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
3749                                  * declaration, so it doesn't generate 'implicit int' followed by more
3750                                  * errors later on. */
3751                                 token_type_t const la1_type = (token_type_t)look_ahead(1)->type;
3752                                 switch (la1_type) {
3753                                         DECLARATION_START
3754                                         case T_IDENTIFIER:
3755                                         case '*': {
3756                                                 errorf(HERE, "%K does not name a type", &token);
3757
3758                                                 entity_t *entity =
3759                                                         create_error_entity(token.v.symbol, ENTITY_TYPEDEF);
3760
3761                                                 type = allocate_type_zero(TYPE_TYPEDEF);
3762                                                 type->typedeft.typedefe = &entity->typedefe;
3763
3764                                                 next_token();
3765                                                 saw_error = true;
3766                                                 if (la1_type == '*')
3767                                                         goto finish_specifiers;
3768                                                 continue;
3769                                         }
3770
3771                                         default:
3772                                                 goto finish_specifiers;
3773                                 }
3774                         }
3775
3776                         next_token();
3777                         type = typedef_type;
3778                         break;
3779                 }
3780
3781                 /* function specifier */
3782                 default:
3783                         goto finish_specifiers;
3784                 }
3785         }
3786
3787 finish_specifiers:
3788         in_gcc_extension = old_gcc_extension;
3789
3790         if (type == NULL || (saw_error && type_specifiers != 0)) {
3791                 atomic_type_kind_t atomic_type;
3792
3793                 /* match valid basic types */
3794                 switch (type_specifiers) {
3795                 case SPECIFIER_VOID:
3796                         atomic_type = ATOMIC_TYPE_VOID;
3797                         break;
3798                 case SPECIFIER_CHAR:
3799                         atomic_type = ATOMIC_TYPE_CHAR;
3800                         break;
3801                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
3802                         atomic_type = ATOMIC_TYPE_SCHAR;
3803                         break;
3804                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
3805                         atomic_type = ATOMIC_TYPE_UCHAR;
3806                         break;
3807                 case SPECIFIER_SHORT:
3808                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
3809                 case SPECIFIER_SHORT | SPECIFIER_INT:
3810                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3811                         atomic_type = ATOMIC_TYPE_SHORT;
3812                         break;
3813                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
3814                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3815                         atomic_type = ATOMIC_TYPE_USHORT;
3816                         break;
3817                 case SPECIFIER_INT:
3818                 case SPECIFIER_SIGNED:
3819                 case SPECIFIER_SIGNED | SPECIFIER_INT:
3820                         atomic_type = ATOMIC_TYPE_INT;
3821                         break;
3822                 case SPECIFIER_UNSIGNED:
3823                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
3824                         atomic_type = ATOMIC_TYPE_UINT;
3825                         break;
3826                 case SPECIFIER_LONG:
3827                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
3828                 case SPECIFIER_LONG | SPECIFIER_INT:
3829                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3830                         atomic_type = ATOMIC_TYPE_LONG;
3831                         break;
3832                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
3833                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3834                         atomic_type = ATOMIC_TYPE_ULONG;
3835                         break;
3836
3837                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3838                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3839                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
3840                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3841                         | SPECIFIER_INT:
3842                         atomic_type = ATOMIC_TYPE_LONGLONG;
3843                         goto warn_about_long_long;
3844
3845                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3846                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3847                         | SPECIFIER_INT:
3848                         atomic_type = ATOMIC_TYPE_ULONGLONG;
3849 warn_about_long_long:
3850                         if (warning.long_long) {
3851                                 warningf(&specifiers->source_position,
3852                                          "ISO C90 does not support 'long long'");
3853                         }
3854                         break;
3855
3856                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
3857                         atomic_type = unsigned_int8_type_kind;
3858                         break;
3859
3860                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
3861                         atomic_type = unsigned_int16_type_kind;
3862                         break;
3863
3864                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
3865                         atomic_type = unsigned_int32_type_kind;
3866                         break;
3867
3868                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
3869                         atomic_type = unsigned_int64_type_kind;
3870                         break;
3871
3872                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
3873                         atomic_type = unsigned_int128_type_kind;
3874                         break;
3875
3876                 case SPECIFIER_INT8:
3877                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
3878                         atomic_type = int8_type_kind;
3879                         break;
3880
3881                 case SPECIFIER_INT16:
3882                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
3883                         atomic_type = int16_type_kind;
3884                         break;
3885
3886                 case SPECIFIER_INT32:
3887                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
3888                         atomic_type = int32_type_kind;
3889                         break;
3890
3891                 case SPECIFIER_INT64:
3892                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
3893                         atomic_type = int64_type_kind;
3894                         break;
3895
3896                 case SPECIFIER_INT128:
3897                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
3898                         atomic_type = int128_type_kind;
3899                         break;
3900
3901                 case SPECIFIER_FLOAT:
3902                         atomic_type = ATOMIC_TYPE_FLOAT;
3903                         break;
3904                 case SPECIFIER_DOUBLE:
3905                         atomic_type = ATOMIC_TYPE_DOUBLE;
3906                         break;
3907                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
3908                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3909                         break;
3910                 case SPECIFIER_BOOL:
3911                         atomic_type = ATOMIC_TYPE_BOOL;
3912                         break;
3913                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
3914                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
3915                         atomic_type = ATOMIC_TYPE_FLOAT;
3916                         break;
3917                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3918                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3919                         atomic_type = ATOMIC_TYPE_DOUBLE;
3920                         break;
3921                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3922                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3923                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3924                         break;
3925                 default:
3926                         /* invalid specifier combination, give an error message */
3927                         if (type_specifiers == 0) {
3928                                 if (saw_error)
3929                                         goto end_error;
3930
3931                                 /* ISO/IEC 14882:1998(E) §C.1.5:4 */
3932                                 if (!(c_mode & _CXX) && !strict_mode) {
3933                                         if (warning.implicit_int) {
3934                                                 warningf(HERE, "no type specifiers in declaration, using 'int'");
3935                                         }
3936                                         atomic_type = ATOMIC_TYPE_INT;
3937                                         break;
3938                                 } else {
3939                                         errorf(HERE, "no type specifiers given in declaration");
3940                                 }
3941                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
3942                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
3943                                 errorf(HERE, "signed and unsigned specifiers given");
3944                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
3945                                 errorf(HERE, "only integer types can be signed or unsigned");
3946                         } else {
3947                                 errorf(HERE, "multiple datatypes in declaration");
3948                         }
3949                         goto end_error;
3950                 }
3951
3952                 if (type_specifiers & SPECIFIER_COMPLEX) {
3953                         type                = allocate_type_zero(TYPE_COMPLEX);
3954                         type->complex.akind = atomic_type;
3955                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
3956                         type                  = allocate_type_zero(TYPE_IMAGINARY);
3957                         type->imaginary.akind = atomic_type;
3958                 } else {
3959                         type               = allocate_type_zero(TYPE_ATOMIC);
3960                         type->atomic.akind = atomic_type;
3961                 }
3962                 newtype = true;
3963         } else if (type_specifiers != 0) {
3964                 errorf(HERE, "multiple datatypes in declaration");
3965         }
3966
3967         /* FIXME: check type qualifiers here */
3968
3969         type->base.qualifiers = qualifiers;
3970         type->base.modifiers  = modifiers;
3971
3972         type_t *result = typehash_insert(type);
3973         if (newtype && result != type) {
3974                 free_type(type);
3975         }
3976
3977         specifiers->type = result;
3978         return;
3979
3980 end_error:
3981         specifiers->type = type_error_type;
3982         return;
3983 }
3984
3985 static type_qualifiers_t parse_type_qualifiers(void)
3986 {
3987         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
3988
3989         while (true) {
3990                 switch (token.type) {
3991                 /* type qualifiers */
3992                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3993                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3994                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3995                 /* microsoft extended type modifiers */
3996                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3997                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3998                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3999                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
4000                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
4001
4002                 default:
4003                         return qualifiers;
4004                 }
4005         }
4006 }
4007
4008 /**
4009  * Parses an K&R identifier list
4010  */
4011 static void parse_identifier_list(scope_t *scope)
4012 {
4013         do {
4014                 entity_t *entity = allocate_entity_zero(ENTITY_VARIABLE);
4015                 entity->base.source_position = token.source_position;
4016                 entity->base.namespc         = NAMESPACE_NORMAL;
4017                 entity->base.symbol          = token.v.symbol;
4018                 /* a K&R parameter has no type, yet */
4019                 next_token();
4020
4021                 append_entity(scope, entity);
4022
4023                 if (token.type != ',') {
4024                         break;
4025                 }
4026                 next_token();
4027         } while (token.type == T_IDENTIFIER);
4028 }
4029
4030 static type_t *automatic_type_conversion(type_t *orig_type);
4031
4032 static void semantic_parameter(declaration_t *declaration)
4033 {
4034         /* TODO: improve error messages */
4035         source_position_t const* const pos = &declaration->base.source_position;
4036
4037         /* §6.9.1:6 */
4038         switch (declaration->declared_storage_class) {
4039                 /* Allowed storage classes */
4040                 case STORAGE_CLASS_NONE:
4041                 case STORAGE_CLASS_REGISTER:
4042                         break;
4043
4044                 default:
4045                         errorf(pos, "parameter may only have none or register storage class");
4046                         break;
4047         }
4048
4049         type_t *const orig_type = declaration->type;
4050         /* §6.7.5.3(7): Array as last part of a parameter type is just syntactic
4051          * sugar.  Turn it into a pointer.
4052          * §6.7.5.3(8): A declaration of a parameter as ``function returning type''
4053          * shall be adjusted to ``pointer to function returning type'', as in 6.3.2.1.
4054          */
4055         type_t *const type = automatic_type_conversion(orig_type);
4056         declaration->type = type;
4057
4058         if (is_type_incomplete(skip_typeref(type))) {
4059                 errorf(pos, "parameter '%#T' is of incomplete type",
4060                        orig_type, declaration->base.symbol);
4061         }
4062 }
4063
4064 static entity_t *parse_parameter(void)
4065 {
4066         declaration_specifiers_t specifiers;
4067         memset(&specifiers, 0, sizeof(specifiers));
4068
4069         parse_declaration_specifiers(&specifiers);
4070
4071         entity_t *entity = parse_declarator(&specifiers, true, false);
4072         anonymous_entity = NULL;
4073         return entity;
4074 }
4075
4076 /**
4077  * Parses function type parameters (and optionally creates variable_t entities
4078  * for them in a scope)
4079  */
4080 static void parse_parameters(function_type_t *type, scope_t *scope)
4081 {
4082         eat('(');
4083         add_anchor_token(')');
4084         int saved_comma_state = save_and_reset_anchor_state(',');
4085
4086         if (token.type == T_IDENTIFIER &&
4087             !is_typedef_symbol(token.v.symbol)) {
4088                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
4089                 if (la1_type == ',' || la1_type == ')') {
4090                         type->kr_style_parameters = true;
4091                         parse_identifier_list(scope);
4092                         goto parameters_finished;
4093                 }
4094         }
4095
4096         if (token.type == ')') {
4097                 /* ISO/IEC 14882:1998(E) §C.1.6:1 */
4098                 if (!(c_mode & _CXX))
4099                         type->unspecified_parameters = true;
4100                 goto parameters_finished;
4101         }
4102
4103         function_parameter_t *parameter;
4104         function_parameter_t *last_parameter = NULL;
4105
4106         while (true) {
4107                 switch (token.type) {
4108                 case T_DOTDOTDOT:
4109                         next_token();
4110                         type->variadic = true;
4111                         goto parameters_finished;
4112
4113                 case T_IDENTIFIER:
4114                 case T___extension__:
4115                 DECLARATION_START
4116                 {
4117                         entity_t *entity = parse_parameter();
4118                         if (entity->kind == ENTITY_TYPEDEF) {
4119                                 errorf(&entity->base.source_position,
4120                                        "typedef not allowed as function parameter");
4121                                 break;
4122                         }
4123                         assert(is_declaration(entity));
4124
4125                         /* func(void) is not a parameter */
4126                         if (last_parameter == NULL
4127                                         && token.type == ')'
4128                                         && entity->base.symbol == NULL
4129                                         && skip_typeref(entity->declaration.type) == type_void) {
4130                                 goto parameters_finished;
4131                         }
4132                         semantic_parameter(&entity->declaration);
4133
4134                         parameter = obstack_alloc(type_obst, sizeof(parameter[0]));
4135                         memset(parameter, 0, sizeof(parameter[0]));
4136                         parameter->type = entity->declaration.type;
4137
4138                         if (scope != NULL) {
4139                                 append_entity(scope, entity);
4140                         }
4141
4142                         if (last_parameter != NULL) {
4143                                 last_parameter->next = parameter;
4144                         } else {
4145                                 type->parameters = parameter;
4146                         }
4147                         last_parameter   = parameter;
4148                         break;
4149                 }
4150
4151                 default:
4152                         goto parameters_finished;
4153                 }
4154                 if (token.type != ',') {
4155                         goto parameters_finished;
4156                 }
4157                 next_token();
4158         }
4159
4160
4161 parameters_finished:
4162         rem_anchor_token(')');
4163         expect(')');
4164
4165 end_error:
4166         restore_anchor_state(',', saved_comma_state);
4167 }
4168
4169 typedef enum construct_type_kind_t {
4170         CONSTRUCT_INVALID,
4171         CONSTRUCT_POINTER,
4172         CONSTRUCT_FUNCTION,
4173         CONSTRUCT_ARRAY
4174 } construct_type_kind_t;
4175
4176 typedef struct construct_type_t construct_type_t;
4177 struct construct_type_t {
4178         construct_type_kind_t  kind;
4179         construct_type_t      *next;
4180 };
4181
4182 typedef struct parsed_pointer_t parsed_pointer_t;
4183 struct parsed_pointer_t {
4184         construct_type_t  construct_type;
4185         type_qualifiers_t type_qualifiers;
4186 };
4187
4188 typedef struct construct_function_type_t construct_function_type_t;
4189 struct construct_function_type_t {
4190         construct_type_t  construct_type;
4191         type_t           *function_type;
4192 };
4193
4194 typedef struct parsed_array_t parsed_array_t;
4195 struct parsed_array_t {
4196         construct_type_t  construct_type;
4197         type_qualifiers_t type_qualifiers;
4198         bool              is_static;
4199         bool              is_variable;
4200         expression_t     *size;
4201 };
4202
4203 typedef struct construct_base_type_t construct_base_type_t;
4204 struct construct_base_type_t {
4205         construct_type_t  construct_type;
4206         type_t           *type;
4207 };
4208
4209 static construct_type_t *parse_pointer_declarator(void)
4210 {
4211         eat('*');
4212
4213         parsed_pointer_t *pointer = obstack_alloc(&temp_obst, sizeof(pointer[0]));
4214         memset(pointer, 0, sizeof(pointer[0]));
4215         pointer->construct_type.kind = CONSTRUCT_POINTER;
4216         pointer->type_qualifiers     = parse_type_qualifiers();
4217
4218         return (construct_type_t*) pointer;
4219 }
4220
4221 static construct_type_t *parse_array_declarator(void)
4222 {
4223         eat('[');
4224         add_anchor_token(']');
4225
4226         parsed_array_t *array = obstack_alloc(&temp_obst, sizeof(array[0]));
4227         memset(array, 0, sizeof(array[0]));
4228         array->construct_type.kind = CONSTRUCT_ARRAY;
4229
4230         if (token.type == T_static) {
4231                 array->is_static = true;
4232                 next_token();
4233         }
4234
4235         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
4236         if (type_qualifiers != 0) {
4237                 if (token.type == T_static) {
4238                         array->is_static = true;
4239                         next_token();
4240                 }
4241         }
4242         array->type_qualifiers = type_qualifiers;
4243
4244         if (token.type == '*' && look_ahead(1)->type == ']') {
4245                 array->is_variable = true;
4246                 next_token();
4247         } else if (token.type != ']') {
4248                 array->size = parse_assignment_expression();
4249         }
4250
4251         rem_anchor_token(']');
4252         expect(']');
4253
4254 end_error:
4255         return (construct_type_t*) array;
4256 }
4257
4258 static construct_type_t *parse_function_declarator(scope_t *scope,
4259                                                    decl_modifiers_t modifiers)
4260 {
4261         type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
4262         function_type_t *ftype = &type->function;
4263
4264         ftype->linkage = current_linkage;
4265
4266         switch (modifiers & (DM_CDECL | DM_STDCALL | DM_FASTCALL | DM_THISCALL)) {
4267                 case DM_NONE:     break;
4268                 case DM_CDECL:    ftype->calling_convention = CC_CDECL;    break;
4269                 case DM_STDCALL:  ftype->calling_convention = CC_STDCALL;  break;
4270                 case DM_FASTCALL: ftype->calling_convention = CC_FASTCALL; break;
4271                 case DM_THISCALL: ftype->calling_convention = CC_THISCALL; break;
4272
4273                 default:
4274                         errorf(HERE, "multiple calling conventions in declaration");
4275                         break;
4276         }
4277
4278         parse_parameters(ftype, scope);
4279
4280         construct_function_type_t *construct_function_type =
4281                 obstack_alloc(&temp_obst, sizeof(construct_function_type[0]));
4282         memset(construct_function_type, 0, sizeof(construct_function_type[0]));
4283         construct_function_type->construct_type.kind = CONSTRUCT_FUNCTION;
4284         construct_function_type->function_type       = type;
4285
4286         return &construct_function_type->construct_type;
4287 }
4288
4289 typedef struct parse_declarator_env_t {
4290         decl_modifiers_t   modifiers;
4291         symbol_t          *symbol;
4292         source_position_t  source_position;
4293         scope_t            parameters;
4294 } parse_declarator_env_t;
4295
4296 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env,
4297                 bool may_be_abstract)
4298 {
4299         /* construct a single linked list of construct_type_t's which describe
4300          * how to construct the final declarator type */
4301         construct_type_t *first      = NULL;
4302         construct_type_t *last       = NULL;
4303         gnu_attribute_t  *attributes = NULL;
4304
4305         decl_modifiers_t modifiers = parse_attributes(&attributes);
4306
4307         /* pointers */
4308         while (token.type == '*') {
4309                 construct_type_t *type = parse_pointer_declarator();
4310
4311                 if (last == NULL) {
4312                         first = type;
4313                         last  = type;
4314                 } else {
4315                         last->next = type;
4316                         last       = type;
4317                 }
4318
4319                 /* TODO: find out if this is correct */
4320                 modifiers |= parse_attributes(&attributes);
4321         }
4322
4323         if (env != NULL) {
4324                 modifiers      |= env->modifiers;
4325                 env->modifiers  = modifiers;
4326         }
4327
4328         construct_type_t *inner_types = NULL;
4329
4330         switch (token.type) {
4331         case T_IDENTIFIER:
4332                 if (env == NULL) {
4333                         errorf(HERE, "no identifier expected in typename");
4334                 } else {
4335                         env->symbol          = token.v.symbol;
4336                         env->source_position = token.source_position;
4337                 }
4338                 next_token();
4339                 break;
4340         case '(':
4341                 next_token();
4342                 add_anchor_token(')');
4343                 inner_types = parse_inner_declarator(env, may_be_abstract);
4344                 if (inner_types != NULL) {
4345                         /* All later declarators only modify the return type */
4346                         env = NULL;
4347                 }
4348                 rem_anchor_token(')');
4349                 expect(')');
4350                 break;
4351         default:
4352                 if (may_be_abstract)
4353                         break;
4354                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
4355                 eat_until_anchor();
4356                 return NULL;
4357         }
4358
4359         construct_type_t *p = last;
4360
4361         while (true) {
4362                 construct_type_t *type;
4363                 switch (token.type) {
4364                 case '(': {
4365                         scope_t *scope = NULL;
4366                         if (env != NULL)
4367                                 scope = &env->parameters;
4368
4369                         type = parse_function_declarator(scope, modifiers);
4370                         break;
4371                 }
4372                 case '[':
4373                         type = parse_array_declarator();
4374                         break;
4375                 default:
4376                         goto declarator_finished;
4377                 }
4378
4379                 /* insert in the middle of the list (behind p) */
4380                 if (p != NULL) {
4381                         type->next = p->next;
4382                         p->next    = type;
4383                 } else {
4384                         type->next = first;
4385                         first      = type;
4386                 }
4387                 if (last == p) {
4388                         last = type;
4389                 }
4390         }
4391
4392 declarator_finished:
4393         /* append inner_types at the end of the list, we don't to set last anymore
4394          * as it's not needed anymore */
4395         if (last == NULL) {
4396                 assert(first == NULL);
4397                 first = inner_types;
4398         } else {
4399                 last->next = inner_types;
4400         }
4401
4402         return first;
4403 end_error:
4404         return NULL;
4405 }
4406
4407 static void parse_declaration_attributes(entity_t *entity)
4408 {
4409         gnu_attribute_t  *attributes = NULL;
4410         decl_modifiers_t  modifiers  = parse_attributes(&attributes);
4411
4412         if (entity == NULL)
4413                 return;
4414
4415         type_t *type;
4416         if (entity->kind == ENTITY_TYPEDEF) {
4417                 modifiers |= entity->typedefe.modifiers;
4418                 type       = entity->typedefe.type;
4419         } else {
4420                 assert(is_declaration(entity));
4421                 modifiers |= entity->declaration.modifiers;
4422                 type       = entity->declaration.type;
4423         }
4424         if (type == NULL)
4425                 return;
4426
4427         /* handle these strange/stupid mode attributes */
4428         gnu_attribute_t *attribute = attributes;
4429         for ( ; attribute != NULL; attribute = attribute->next) {
4430                 if (attribute->kind != GNU_AK_MODE || attribute->invalid)
4431                         continue;
4432
4433                 atomic_type_kind_t  akind = attribute->u.akind;
4434                 if (!is_type_signed(type)) {
4435                         switch (akind) {
4436                         case ATOMIC_TYPE_CHAR: akind = ATOMIC_TYPE_UCHAR; break;
4437                         case ATOMIC_TYPE_SHORT: akind = ATOMIC_TYPE_USHORT; break;
4438                         case ATOMIC_TYPE_INT: akind = ATOMIC_TYPE_UINT; break;
4439                         case ATOMIC_TYPE_LONGLONG: akind = ATOMIC_TYPE_ULONGLONG; break;
4440                         default:
4441                                 panic("invalid akind in mode attribute");
4442                         }
4443                 } else {
4444                         switch (akind) {
4445                         case ATOMIC_TYPE_CHAR: akind = ATOMIC_TYPE_SCHAR; break;
4446                         case ATOMIC_TYPE_SHORT: akind = ATOMIC_TYPE_SHORT; break;
4447                         case ATOMIC_TYPE_INT: akind = ATOMIC_TYPE_INT; break;
4448                         case ATOMIC_TYPE_LONGLONG: akind = ATOMIC_TYPE_LONGLONG; break;
4449                         default:
4450                                 panic("invalid akind in mode attribute");
4451                         }
4452                 }
4453
4454                 type = make_atomic_type(akind, type->base.qualifiers);
4455         }
4456
4457         type_modifiers_t type_modifiers = type->base.modifiers;
4458         if (modifiers & DM_TRANSPARENT_UNION)
4459                 modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
4460
4461         if (type->base.modifiers != type_modifiers) {
4462                 type_t *copy = duplicate_type(type);
4463                 copy->base.modifiers = type_modifiers;
4464
4465                 type = typehash_insert(copy);
4466                 if (type != copy) {
4467                         obstack_free(type_obst, copy);
4468                 }
4469         }
4470
4471         if (entity->kind == ENTITY_TYPEDEF) {
4472                 entity->typedefe.type      = type;
4473                 entity->typedefe.modifiers = modifiers;
4474         } else {
4475                 entity->declaration.type      = type;
4476                 entity->declaration.modifiers = modifiers;
4477         }
4478 }
4479
4480 static type_t *construct_declarator_type(construct_type_t *construct_list,
4481                                          type_t *type, variable_t *variable)
4482 {
4483         construct_type_t *iter = construct_list;
4484         for (; iter != NULL; iter = iter->next) {
4485                 switch (iter->kind) {
4486                 case CONSTRUCT_INVALID:
4487                         internal_errorf(HERE, "invalid type construction found");
4488                 case CONSTRUCT_FUNCTION: {
4489                         construct_function_type_t *construct_function_type
4490                                 = (construct_function_type_t*) iter;
4491
4492                         type_t *function_type = construct_function_type->function_type;
4493
4494                         function_type->function.return_type = type;
4495
4496                         type_t *skipped_return_type = skip_typeref(type);
4497                         /* §6.7.5.3(1) */
4498                         if (is_type_function(skipped_return_type)) {
4499                                 errorf(HERE, "function returning function is not allowed");
4500                         } else if (is_type_array(skipped_return_type)) {
4501                                 errorf(HERE, "function returning array is not allowed");
4502                         } else {
4503                                 if (skipped_return_type->base.qualifiers != 0 && warning.other) {
4504                                         warningf(HERE,
4505                                                 "type qualifiers in return type of function type are meaningless");
4506                                 }
4507                         }
4508
4509                         type = function_type;
4510                         break;
4511                 }
4512
4513                 case CONSTRUCT_POINTER: {
4514                         parsed_pointer_t *parsed_pointer = (parsed_pointer_t*) iter;
4515                         type = make_based_pointer_type(type, parsed_pointer->type_qualifiers, variable);
4516                         continue;
4517                 }
4518
4519                 case CONSTRUCT_ARRAY: {
4520                         parsed_array_t *parsed_array  = (parsed_array_t*) iter;
4521                         type_t         *array_type    = allocate_type_zero(TYPE_ARRAY);
4522
4523                         expression_t *size_expression = parsed_array->size;
4524                         if (size_expression != NULL) {
4525                                 size_expression
4526                                         = create_implicit_cast(size_expression, type_size_t);
4527                         }
4528
4529                         array_type->base.qualifiers       = parsed_array->type_qualifiers;
4530                         array_type->array.element_type    = type;
4531                         array_type->array.is_static       = parsed_array->is_static;
4532                         array_type->array.is_variable     = parsed_array->is_variable;
4533                         array_type->array.size_expression = size_expression;
4534
4535                         if (size_expression != NULL) {
4536                                 if (is_constant_expression(size_expression)) {
4537                                         array_type->array.size_constant = true;
4538                                         array_type->array.size
4539                                                 = fold_constant(size_expression);
4540                                 } else {
4541                                         array_type->array.is_vla = true;
4542                                 }
4543                         }
4544
4545                         type_t *skipped_type = skip_typeref(type);
4546                         /* §6.7.5.2(1) */
4547                         if (is_type_incomplete(skipped_type)) {
4548                                 errorf(HERE, "array of incomplete type '%T' is not allowed", type);
4549                         } else if (is_type_function(skipped_type)) {
4550                                 errorf(HERE, "array of functions is not allowed");
4551                         }
4552                         type = array_type;
4553                         break;
4554                 }
4555                 }
4556
4557                 type_t *hashed_type = typehash_insert(type);
4558                 if (hashed_type != type) {
4559                         /* the function type was constructed earlier freeing it here will
4560                          * destroy other types... */
4561                         if (iter->kind != CONSTRUCT_FUNCTION) {
4562                                 free_type(type);
4563                         }
4564                         type = hashed_type;
4565                 }
4566         }
4567
4568         return type;
4569 }
4570
4571 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
4572                                   bool may_be_abstract,
4573                                   bool create_compound_member)
4574 {
4575         parse_declarator_env_t env;
4576         memset(&env, 0, sizeof(env));
4577         env.modifiers = specifiers->modifiers;
4578
4579         construct_type_t *construct_type
4580                 = parse_inner_declarator(&env, may_be_abstract);
4581         type_t *type = construct_declarator_type(construct_type, specifiers->type, specifiers->based_variable);
4582
4583         if (construct_type != NULL) {
4584                 obstack_free(&temp_obst, construct_type);
4585         }
4586
4587         entity_t *entity;
4588         if (specifiers->storage_class == STORAGE_CLASS_TYPEDEF) {
4589                 entity                       = allocate_entity_zero(ENTITY_TYPEDEF);
4590                 entity->base.symbol          = env.symbol;
4591                 entity->base.source_position = env.source_position;
4592                 entity->typedefe.type        = type;
4593
4594                 if (anonymous_entity != NULL) {
4595                         if (is_type_compound(type)) {
4596                                 assert(anonymous_entity->compound.alias == NULL);
4597                                 assert(anonymous_entity->kind == ENTITY_STRUCT ||
4598                                        anonymous_entity->kind == ENTITY_UNION);
4599                                 anonymous_entity->compound.alias = entity;
4600                                 anonymous_entity = NULL;
4601                         } else if (is_type_enum(type)) {
4602                                 assert(anonymous_entity->enume.alias == NULL);
4603                                 assert(anonymous_entity->kind == ENTITY_ENUM);
4604                                 anonymous_entity->enume.alias = entity;
4605                                 anonymous_entity = NULL;
4606                         }
4607                 }
4608         } else {
4609                 if (create_compound_member) {
4610                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER);
4611                 } else if (is_type_function(skip_typeref(type))) {
4612                         entity = allocate_entity_zero(ENTITY_FUNCTION);
4613
4614                         entity->function.is_inline  = specifiers->is_inline;
4615                         entity->function.parameters = env.parameters;
4616                 } else {
4617                         entity = allocate_entity_zero(ENTITY_VARIABLE);
4618
4619                         entity->variable.get_property_sym = specifiers->get_property_sym;
4620                         entity->variable.put_property_sym = specifiers->put_property_sym;
4621                         if (specifiers->alignment != 0) {
4622                                 /* TODO: add checks here */
4623                                 entity->variable.alignment = specifiers->alignment;
4624                         }
4625
4626                         if (warning.other && specifiers->is_inline && is_type_valid(type)) {
4627                                 warningf(&env.source_position,
4628                                                  "variable '%Y' declared 'inline'\n", env.symbol);
4629                         }
4630                 }
4631
4632                 entity->base.source_position          = env.source_position;
4633                 entity->base.symbol                   = env.symbol;
4634                 entity->base.namespc                  = NAMESPACE_NORMAL;
4635                 entity->declaration.type              = type;
4636                 entity->declaration.modifiers         = env.modifiers;
4637                 entity->declaration.deprecated_string = specifiers->deprecated_string;
4638
4639                 storage_class_t storage_class = specifiers->storage_class;
4640                 entity->declaration.declared_storage_class = storage_class;
4641
4642                 if (storage_class == STORAGE_CLASS_NONE
4643                                 && current_scope != file_scope) {
4644                         storage_class = STORAGE_CLASS_AUTO;
4645                 }
4646                 entity->declaration.storage_class = storage_class;
4647         }
4648
4649         parse_declaration_attributes(entity);
4650
4651         return entity;
4652 }
4653
4654 static type_t *parse_abstract_declarator(type_t *base_type)
4655 {
4656         construct_type_t *construct_type = parse_inner_declarator(NULL, 1);
4657
4658         type_t *result = construct_declarator_type(construct_type, base_type, NULL);
4659         if (construct_type != NULL) {
4660                 obstack_free(&temp_obst, construct_type);
4661         }
4662
4663         return result;
4664 }
4665
4666 /**
4667  * Check if the declaration of main is suspicious.  main should be a
4668  * function with external linkage, returning int, taking either zero
4669  * arguments, two, or three arguments of appropriate types, ie.
4670  *
4671  * int main([ int argc, char **argv [, char **env ] ]).
4672  *
4673  * @param decl    the declaration to check
4674  * @param type    the function type of the declaration
4675  */
4676 static void check_type_of_main(const entity_t *entity)
4677 {
4678         const source_position_t *pos = &entity->base.source_position;
4679         if (entity->kind != ENTITY_FUNCTION) {
4680                 warningf(pos, "'main' is not a function");
4681                 return;
4682         }
4683
4684         if (entity->declaration.storage_class == STORAGE_CLASS_STATIC) {
4685                 warningf(pos, "'main' is normally a non-static function");
4686         }
4687
4688         type_t *type = skip_typeref(entity->declaration.type);
4689         assert(is_type_function(type));
4690
4691         function_type_t *func_type = &type->function;
4692         if (!types_compatible(skip_typeref(func_type->return_type), type_int)) {
4693                 warningf(pos, "return type of 'main' should be 'int', but is '%T'",
4694                          func_type->return_type);
4695         }
4696         const function_parameter_t *parm = func_type->parameters;
4697         if (parm != NULL) {
4698                 type_t *const first_type = parm->type;
4699                 if (!types_compatible(skip_typeref(first_type), type_int)) {
4700                         warningf(pos,
4701                                  "first argument of 'main' should be 'int', but is '%T'",
4702                                  first_type);
4703                 }
4704                 parm = parm->next;
4705                 if (parm != NULL) {
4706                         type_t *const second_type = parm->type;
4707                         if (!types_compatible(skip_typeref(second_type), type_char_ptr_ptr)) {
4708                                 warningf(pos, "second argument of 'main' should be 'char**', but is '%T'", second_type);
4709                         }
4710                         parm = parm->next;
4711                         if (parm != NULL) {
4712                                 type_t *const third_type = parm->type;
4713                                 if (!types_compatible(skip_typeref(third_type), type_char_ptr_ptr)) {
4714                                         warningf(pos, "third argument of 'main' should be 'char**', but is '%T'", third_type);
4715                                 }
4716                                 parm = parm->next;
4717                                 if (parm != NULL)
4718                                         goto warn_arg_count;
4719                         }
4720                 } else {
4721 warn_arg_count:
4722                         warningf(pos, "'main' takes only zero, two or three arguments");
4723                 }
4724         }
4725 }
4726
4727 /**
4728  * Check if a symbol is the equal to "main".
4729  */
4730 static bool is_sym_main(const symbol_t *const sym)
4731 {
4732         return strcmp(sym->string, "main") == 0;
4733 }
4734
4735 static const char *get_entity_kind_name(entity_kind_t kind)
4736 {
4737         switch ((entity_kind_tag_t) kind) {
4738         case ENTITY_FUNCTION:        return "function";
4739         case ENTITY_VARIABLE:        return "variable";
4740         case ENTITY_COMPOUND_MEMBER: return "compound type member";
4741         case ENTITY_STRUCT:          return "struct";
4742         case ENTITY_UNION:           return "union";
4743         case ENTITY_ENUM:            return "enum";
4744         case ENTITY_ENUM_VALUE:      return "enum value";
4745         case ENTITY_LABEL:           return "label";
4746         case ENTITY_LOCAL_LABEL:     return "local label";
4747         case ENTITY_TYPEDEF:         return "typedef";
4748         case ENTITY_NAMESPACE:       return "namespace";
4749         case ENTITY_INVALID:         break;
4750         }
4751
4752         panic("Invalid entity kind encountered in get_entity_kind_name");
4753 }
4754
4755 static void error_redefined_as_different_kind(const source_position_t *pos,
4756                 const entity_t *old, entity_kind_t new_kind)
4757 {
4758         errorf(pos, "redeclaration of %s '%Y' as %s (declared %P)",
4759                get_entity_kind_name(old->kind), old->base.symbol,
4760                get_entity_kind_name(new_kind), &old->base.source_position);
4761 }
4762
4763 /**
4764  * record entities for the NAMESPACE_NORMAL, and produce error messages/warnings
4765  * for various problems that occur for multiple definitions
4766  */
4767 static entity_t *record_entity(entity_t *entity, const bool is_definition)
4768 {
4769         const symbol_t *const    symbol  = entity->base.symbol;
4770         const namespace_tag_t    namespc = (namespace_tag_t)entity->base.namespc;
4771         const source_position_t *pos     = &entity->base.source_position;
4772
4773         assert(symbol != NULL);
4774         entity_t *previous_entity = get_entity(symbol, namespc);
4775         /* pushing the same entity twice will break the stack structure */
4776         assert(previous_entity != entity);
4777
4778         if (entity->kind == ENTITY_FUNCTION) {
4779                 type_t *const orig_type = entity->declaration.type;
4780                 type_t *const type      = skip_typeref(orig_type);
4781
4782                 assert(is_type_function(type));
4783                 if (type->function.unspecified_parameters &&
4784                                 warning.strict_prototypes &&
4785                                 previous_entity == NULL) {
4786                         warningf(pos, "function declaration '%#T' is not a prototype",
4787                                          orig_type, symbol);
4788                 }
4789
4790                 if (warning.main && current_scope == file_scope
4791                                 && is_sym_main(symbol)) {
4792                         check_type_of_main(entity);
4793                 }
4794         }
4795
4796         if (is_declaration(entity)) {
4797                 if (warning.nested_externs
4798                                 && entity->declaration.storage_class == STORAGE_CLASS_EXTERN
4799                                 && current_scope != file_scope) {
4800                         warningf(pos, "nested extern declaration of '%#T'",
4801                                  entity->declaration.type, symbol);
4802                 }
4803         }
4804
4805         if (previous_entity != NULL
4806             && previous_entity->base.parent_scope == &current_function->parameters
4807                 && current_scope->depth == previous_entity->base.parent_scope->depth+1){
4808
4809                 assert(previous_entity->kind == ENTITY_VARIABLE);
4810                 errorf(pos,
4811                        "declaration '%#T' redeclares the parameter '%#T' (declared %P)",
4812                        entity->declaration.type, symbol,
4813                            previous_entity->declaration.type, symbol,
4814                            &previous_entity->base.source_position);
4815                 goto finish;
4816         }
4817
4818         if (previous_entity != NULL
4819                         && previous_entity->base.parent_scope == current_scope) {
4820
4821                 if (previous_entity->kind != entity->kind) {
4822                         error_redefined_as_different_kind(pos, previous_entity,
4823                                                           entity->kind);
4824                         goto finish;
4825                 }
4826                 if (previous_entity->kind == ENTITY_ENUM_VALUE) {
4827                         errorf(pos,
4828                                    "redeclaration of enum entry '%Y' (declared %P)",
4829                                    symbol, &previous_entity->base.source_position);
4830                         goto finish;
4831                 }
4832                 if (previous_entity->kind == ENTITY_TYPEDEF) {
4833                         /* TODO: C++ allows this for exactly the same type */
4834                         errorf(pos,
4835                                "redefinition of typedef '%Y' (declared %P)",
4836                                symbol, &previous_entity->base.source_position);
4837                         goto finish;
4838                 }
4839
4840                 /* at this point we should have only VARIABLES or FUNCTIONS */
4841                 assert(is_declaration(previous_entity) && is_declaration(entity));
4842
4843                 /* can happen for K&R style declarations */
4844                 if (previous_entity->kind == ENTITY_VARIABLE
4845                                 && previous_entity->declaration.type == NULL
4846                                 && entity->kind == ENTITY_VARIABLE) {
4847                         previous_entity->declaration.type = entity->declaration.type;
4848                         previous_entity->declaration.storage_class
4849                                 = entity->declaration.storage_class;
4850                         previous_entity->declaration.declared_storage_class
4851                                 = entity->declaration.declared_storage_class;
4852                         previous_entity->declaration.modifiers
4853                                 = entity->declaration.modifiers;
4854                         previous_entity->declaration.deprecated_string
4855                                 = entity->declaration.deprecated_string;
4856                 }
4857                 assert(entity->declaration.type != NULL);
4858
4859                 declaration_t *const previous_declaration
4860                         = &previous_entity->declaration;
4861                 declaration_t *const declaration = &entity->declaration;
4862                 type_t *const orig_type = entity->declaration.type;
4863                 type_t *const type      = skip_typeref(orig_type);
4864
4865                 type_t *prev_type       = skip_typeref(previous_declaration->type);
4866
4867                 if (!types_compatible(type, prev_type)) {
4868                         errorf(pos,
4869                                    "declaration '%#T' is incompatible with '%#T' (declared %P)",
4870                                    orig_type, symbol, previous_declaration->type, symbol,
4871                                    &previous_entity->base.source_position);
4872                 } else {
4873                         unsigned old_storage_class = previous_declaration->storage_class;
4874                         if (warning.redundant_decls     && is_definition
4875                                 && previous_declaration->storage_class == STORAGE_CLASS_STATIC
4876                                 && !(previous_declaration->modifiers & DM_USED)
4877                                 && !previous_declaration->used) {
4878                                 warningf(&previous_entity->base.source_position,
4879                                          "unnecessary static forward declaration for '%#T'",
4880                                          previous_declaration->type, symbol);
4881                         }
4882
4883                         unsigned new_storage_class = declaration->storage_class;
4884                         if (is_type_incomplete(prev_type)) {
4885                                 previous_declaration->type = type;
4886                                 prev_type                  = type;
4887                         }
4888
4889                         /* pretend no storage class means extern for function
4890                          * declarations (except if the previous declaration is neither
4891                          * none nor extern) */
4892                         if (entity->kind == ENTITY_FUNCTION) {
4893                                 if (prev_type->function.unspecified_parameters) {
4894                                         previous_declaration->type = type;
4895                                         prev_type                  = type;
4896                                 }
4897
4898                                 switch (old_storage_class) {
4899                                 case STORAGE_CLASS_NONE:
4900                                         old_storage_class = STORAGE_CLASS_EXTERN;
4901                                         /* FALLTHROUGH */
4902
4903                                 case STORAGE_CLASS_EXTERN:
4904                                         if (is_definition) {
4905                                                 if (warning.missing_prototypes &&
4906                                                     prev_type->function.unspecified_parameters &&
4907                                                     !is_sym_main(symbol)) {
4908                                                         warningf(pos, "no previous prototype for '%#T'",
4909                                                                          orig_type, symbol);
4910                                                 }
4911                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
4912                                                 new_storage_class = STORAGE_CLASS_EXTERN;
4913                                         }
4914                                         break;
4915
4916                                 default:
4917                                         break;
4918                                 }
4919                         }
4920
4921                         if (old_storage_class == STORAGE_CLASS_EXTERN &&
4922                                         new_storage_class == STORAGE_CLASS_EXTERN) {
4923 warn_redundant_declaration:
4924                                 if (!is_definition           &&
4925                                     warning.redundant_decls  &&
4926                                     is_type_valid(prev_type) &&
4927                                     strcmp(previous_entity->base.source_position.input_name, "<builtin>") != 0) {
4928                                         warningf(pos,
4929                                                  "redundant declaration for '%Y' (declared %P)",
4930                                                  symbol, &previous_entity->base.source_position);
4931                                 }
4932                         } else if (current_function == NULL) {
4933                                 if (old_storage_class != STORAGE_CLASS_STATIC &&
4934                                     new_storage_class == STORAGE_CLASS_STATIC) {
4935                                         errorf(pos,
4936                                                "static declaration of '%Y' follows non-static declaration (declared %P)",
4937                                                symbol, &previous_entity->base.source_position);
4938                                 } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
4939                                         previous_declaration->storage_class          = STORAGE_CLASS_NONE;
4940                                         previous_declaration->declared_storage_class = STORAGE_CLASS_NONE;
4941                                 } else {
4942                                         /* ISO/IEC 14882:1998(E) §C.1.2:1 */
4943                                         if (c_mode & _CXX)
4944                                                 goto error_redeclaration;
4945                                         goto warn_redundant_declaration;
4946                                 }
4947                         } else if (is_type_valid(prev_type)) {
4948                                 if (old_storage_class == new_storage_class) {
4949 error_redeclaration:
4950                                         errorf(pos, "redeclaration of '%Y' (declared %P)",
4951                                                symbol, &previous_entity->base.source_position);
4952                                 } else {
4953                                         errorf(pos,
4954                                                "redeclaration of '%Y' with different linkage (declared %P)",
4955                                                symbol, &previous_entity->base.source_position);
4956                                 }
4957                         }
4958                 }
4959
4960                 previous_declaration->modifiers |= declaration->modifiers;
4961                 if (entity->kind == ENTITY_FUNCTION) {
4962                         previous_entity->function.is_inline |= entity->function.is_inline;
4963                 }
4964                 return previous_entity;
4965         }
4966
4967         if (entity->kind == ENTITY_FUNCTION) {
4968                 if (is_definition &&
4969                                 entity->declaration.storage_class != STORAGE_CLASS_STATIC) {
4970                         if (warning.missing_prototypes && !is_sym_main(symbol)) {
4971                                 warningf(pos, "no previous prototype for '%#T'",
4972                                          entity->declaration.type, symbol);
4973                         } else if (warning.missing_declarations && !is_sym_main(symbol)) {
4974                                 warningf(pos, "no previous declaration for '%#T'",
4975                                          entity->declaration.type, symbol);
4976                         }
4977                 }
4978         } else if (warning.missing_declarations
4979                         && entity->kind == ENTITY_VARIABLE
4980                         && current_scope == file_scope) {
4981                 declaration_t *declaration = &entity->declaration;
4982                 if (declaration->storage_class == STORAGE_CLASS_NONE ||
4983                                 declaration->storage_class == STORAGE_CLASS_THREAD) {
4984                         warningf(pos, "no previous declaration for '%#T'",
4985                                  declaration->type, symbol);
4986                 }
4987         }
4988
4989 finish:
4990         assert(entity->base.parent_scope == NULL);
4991         assert(current_scope != NULL);
4992
4993         entity->base.parent_scope = current_scope;
4994         entity->base.namespc      = NAMESPACE_NORMAL;
4995         environment_push(entity);
4996         append_entity(current_scope, entity);
4997
4998         return entity;
4999 }
5000
5001 static void parser_error_multiple_definition(entity_t *entity,
5002                 const source_position_t *source_position)
5003 {
5004         errorf(source_position, "multiple definition of symbol '%Y' (declared %P)",
5005                entity->base.symbol, &entity->base.source_position);
5006 }
5007
5008 static bool is_declaration_specifier(const token_t *token,
5009                                      bool only_specifiers_qualifiers)
5010 {
5011         switch (token->type) {
5012                 TYPE_SPECIFIERS
5013                 TYPE_QUALIFIERS
5014                         return true;
5015                 case T_IDENTIFIER:
5016                         return is_typedef_symbol(token->v.symbol);
5017
5018                 case T___extension__:
5019                 STORAGE_CLASSES
5020                         return !only_specifiers_qualifiers;
5021
5022                 default:
5023                         return false;
5024         }
5025 }
5026
5027 static void parse_init_declarator_rest(entity_t *entity)
5028 {
5029         assert(is_declaration(entity));
5030         declaration_t *const declaration = &entity->declaration;
5031
5032         eat('=');
5033
5034         type_t *orig_type = declaration->type;
5035         type_t *type      = skip_typeref(orig_type);
5036
5037         if (entity->kind == ENTITY_VARIABLE
5038                         && entity->variable.initializer != NULL) {
5039                 parser_error_multiple_definition(entity, HERE);
5040         }
5041
5042         bool must_be_constant = false;
5043         if (declaration->storage_class == STORAGE_CLASS_STATIC        ||
5044             declaration->storage_class == STORAGE_CLASS_THREAD_STATIC ||
5045             entity->base.parent_scope  == file_scope) {
5046                 must_be_constant = true;
5047         }
5048
5049         if (is_type_function(type)) {
5050                 errorf(&entity->base.source_position,
5051                        "function '%#T' is initialized like a variable",
5052                        orig_type, entity->base.symbol);
5053                 orig_type = type_error_type;
5054         }
5055
5056         parse_initializer_env_t env;
5057         env.type             = orig_type;
5058         env.must_be_constant = must_be_constant;
5059         env.entity           = entity;
5060         current_init_decl    = entity;
5061
5062         initializer_t *initializer = parse_initializer(&env);
5063         current_init_decl = NULL;
5064
5065         if (entity->kind == ENTITY_VARIABLE) {
5066                 /* § 6.7.5 (22)  array initializers for arrays with unknown size
5067                  * determine the array type size */
5068                 declaration->type            = env.type;
5069                 entity->variable.initializer = initializer;
5070         }
5071 }
5072
5073 /* parse rest of a declaration without any declarator */
5074 static void parse_anonymous_declaration_rest(
5075                 const declaration_specifiers_t *specifiers)
5076 {
5077         eat(';');
5078
5079         if (warning.other) {
5080                 if (specifiers->storage_class != STORAGE_CLASS_NONE) {
5081                         warningf(&specifiers->source_position,
5082                                  "useless storage class in empty declaration");
5083                 }
5084
5085                 type_t *type = specifiers->type;
5086                 switch (type->kind) {
5087                         case TYPE_COMPOUND_STRUCT:
5088                         case TYPE_COMPOUND_UNION: {
5089                                 if (type->compound.compound->base.symbol == NULL) {
5090                                         warningf(&specifiers->source_position,
5091                                                  "unnamed struct/union that defines no instances");
5092                                 }
5093                                 break;
5094                         }
5095
5096                         case TYPE_ENUM:
5097                                 break;
5098
5099                         default:
5100                                 warningf(&specifiers->source_position, "empty declaration");
5101                                 break;
5102                 }
5103         }
5104 }
5105
5106 static void parse_declaration_rest(entity_t *ndeclaration,
5107                 const declaration_specifiers_t *specifiers,
5108                 parsed_declaration_func finished_declaration)
5109 {
5110         add_anchor_token(';');
5111         add_anchor_token(',');
5112         while (true) {
5113                 entity_t *entity = finished_declaration(ndeclaration, token.type == '=');
5114
5115                 if (token.type == '=') {
5116                         parse_init_declarator_rest(entity);
5117                 }
5118
5119                 if (token.type != ',')
5120                         break;
5121                 eat(',');
5122
5123                 add_anchor_token('=');
5124                 ndeclaration = parse_declarator(specifiers, /*may_be_abstract=*/false, false);
5125                 rem_anchor_token('=');
5126         }
5127         expect(';');
5128
5129 end_error:
5130         anonymous_entity = NULL;
5131         rem_anchor_token(';');
5132         rem_anchor_token(',');
5133 }
5134
5135 static entity_t *finished_kr_declaration(entity_t *entity, bool is_definition)
5136 {
5137         symbol_t *symbol = entity->base.symbol;
5138         if (symbol == NULL) {
5139                 errorf(HERE, "anonymous declaration not valid as function parameter");
5140                 return entity;
5141         }
5142
5143         assert(entity->base.namespc == NAMESPACE_NORMAL);
5144         entity_t *previous_entity = get_entity(symbol, NAMESPACE_NORMAL);
5145         if (previous_entity == NULL
5146                         || previous_entity->base.parent_scope != current_scope) {
5147                 errorf(HERE, "expected declaration of a function parameter, found '%Y'",
5148                        symbol);
5149                 return entity;
5150         }
5151
5152         if (is_definition) {
5153                 errorf(HERE, "parameter %Y is initialised", entity->base.symbol);
5154         }
5155
5156         return record_entity(entity, false);
5157 }
5158
5159 static void parse_declaration(parsed_declaration_func finished_declaration)
5160 {
5161         declaration_specifiers_t specifiers;
5162         memset(&specifiers, 0, sizeof(specifiers));
5163
5164         add_anchor_token(';');
5165         parse_declaration_specifiers(&specifiers);
5166         rem_anchor_token(';');
5167
5168         if (token.type == ';') {
5169                 parse_anonymous_declaration_rest(&specifiers);
5170         } else {
5171                 entity_t *entity = parse_declarator(&specifiers, /*may_be_abstract=*/false, false);
5172                 parse_declaration_rest(entity, &specifiers, finished_declaration);
5173         }
5174 }
5175
5176 static type_t *get_default_promoted_type(type_t *orig_type)
5177 {
5178         type_t *result = orig_type;
5179
5180         type_t *type = skip_typeref(orig_type);
5181         if (is_type_integer(type)) {
5182                 result = promote_integer(type);
5183         } else if (type == type_float) {
5184                 result = type_double;
5185         }
5186
5187         return result;
5188 }
5189
5190 static void parse_kr_declaration_list(entity_t *entity)
5191 {
5192         if (entity->kind != ENTITY_FUNCTION)
5193                 return;
5194
5195         type_t *type = skip_typeref(entity->declaration.type);
5196         assert(is_type_function(type));
5197         if (!type->function.kr_style_parameters)
5198                 return;
5199
5200
5201         add_anchor_token('{');
5202
5203         /* push function parameters */
5204         size_t const top = environment_top();
5205         scope_push(&entity->function.parameters);
5206
5207         entity_t *parameter = entity->function.parameters.entities;
5208         for ( ; parameter != NULL; parameter = parameter->base.next) {
5209                 assert(parameter->base.parent_scope == NULL);
5210                 parameter->base.parent_scope = current_scope;
5211                 environment_push(parameter);
5212         }
5213
5214         /* parse declaration list */
5215         while (is_declaration_specifier(&token, false)) {
5216                 parse_declaration(finished_kr_declaration);
5217         }
5218
5219         /* pop function parameters */
5220         assert(current_scope == &entity->function.parameters);
5221         scope_pop();
5222         environment_pop_to(top);
5223
5224         /* update function type */
5225         type_t *new_type = duplicate_type(type);
5226
5227         function_parameter_t *parameters     = NULL;
5228         function_parameter_t *last_parameter = NULL;
5229
5230         entity_t *parameter_declaration = entity->function.parameters.entities;
5231         for (; parameter_declaration != NULL;
5232                         parameter_declaration = parameter_declaration->base.next) {
5233                 type_t *parameter_type = parameter_declaration->declaration.type;
5234                 if (parameter_type == NULL) {
5235                         if (strict_mode) {
5236                                 errorf(HERE, "no type specified for function parameter '%Y'",
5237                                        parameter_declaration->base.symbol);
5238                         } else {
5239                                 if (warning.implicit_int) {
5240                                         warningf(HERE, "no type specified for function parameter '%Y', using 'int'",
5241                                                  parameter_declaration->base.symbol);
5242                                 }
5243                                 parameter_type                          = type_int;
5244                                 parameter_declaration->declaration.type = parameter_type;
5245                         }
5246                 }
5247
5248                 semantic_parameter(&parameter_declaration->declaration);
5249                 parameter_type = parameter_declaration->declaration.type;
5250
5251                 /*
5252                  * we need the default promoted types for the function type
5253                  */
5254                 parameter_type = get_default_promoted_type(parameter_type);
5255
5256                 function_parameter_t *function_parameter
5257                         = obstack_alloc(type_obst, sizeof(function_parameter[0]));
5258                 memset(function_parameter, 0, sizeof(function_parameter[0]));
5259
5260                 function_parameter->type = parameter_type;
5261                 if (last_parameter != NULL) {
5262                         last_parameter->next = function_parameter;
5263                 } else {
5264                         parameters = function_parameter;
5265                 }
5266                 last_parameter = function_parameter;
5267         }
5268
5269         /* § 6.9.1.7: A K&R style parameter list does NOT act as a function
5270          * prototype */
5271         new_type->function.parameters             = parameters;
5272         new_type->function.unspecified_parameters = true;
5273
5274         type = typehash_insert(new_type);
5275         if (type != new_type) {
5276                 obstack_free(type_obst, new_type);
5277         }
5278
5279         entity->declaration.type = type;
5280
5281         rem_anchor_token('{');
5282 }
5283
5284 static bool first_err = true;
5285
5286 /**
5287  * When called with first_err set, prints the name of the current function,
5288  * else does noting.
5289  */
5290 static void print_in_function(void)
5291 {
5292         if (first_err) {
5293                 first_err = false;
5294                 diagnosticf("%s: In function '%Y':\n",
5295                             current_function->base.base.source_position.input_name,
5296                             current_function->base.base.symbol);
5297         }
5298 }
5299
5300 /**
5301  * Check if all labels are defined in the current function.
5302  * Check if all labels are used in the current function.
5303  */
5304 static void check_labels(void)
5305 {
5306         for (const goto_statement_t *goto_statement = goto_first;
5307             goto_statement != NULL;
5308             goto_statement = goto_statement->next) {
5309                 /* skip computed gotos */
5310                 if (goto_statement->expression != NULL)
5311                         continue;
5312
5313                 label_t *label = goto_statement->label;
5314
5315                 label->used = true;
5316                 if (label->base.source_position.input_name == NULL) {
5317                         print_in_function();
5318                         errorf(&goto_statement->base.source_position,
5319                                "label '%Y' used but not defined", label->base.symbol);
5320                  }
5321         }
5322
5323         if (warning.unused_label) {
5324                 for (const label_statement_t *label_statement = label_first;
5325                          label_statement != NULL;
5326                          label_statement = label_statement->next) {
5327                         label_t *label = label_statement->label;
5328
5329                         if (! label->used) {
5330                                 print_in_function();
5331                                 warningf(&label_statement->base.source_position,
5332                                          "label '%Y' defined but not used", label->base.symbol);
5333                         }
5334                 }
5335         }
5336 }
5337
5338 static void warn_unused_decl(entity_t *entity, entity_t *end,
5339                              char const *const what)
5340 {
5341         for (; entity != NULL; entity = entity->base.next) {
5342                 if (!is_declaration(entity))
5343                         continue;
5344
5345                 declaration_t *declaration = &entity->declaration;
5346                 if (declaration->implicit)
5347                         continue;
5348
5349                 if (!declaration->used) {
5350                         print_in_function();
5351                         warningf(&entity->base.source_position, "%s '%Y' is unused",
5352                                  what, entity->base.symbol);
5353                 } else if (entity->kind == ENTITY_VARIABLE && !entity->variable.read) {
5354                         print_in_function();
5355                         warningf(&entity->base.source_position, "%s '%Y' is never read",
5356                                  what, entity->base.symbol);
5357                 }
5358
5359                 if (entity == end)
5360                         break;
5361         }
5362 }
5363
5364 static void check_unused_variables(statement_t *const stmt, void *const env)
5365 {
5366         (void)env;
5367
5368         switch (stmt->kind) {
5369                 case STATEMENT_DECLARATION: {
5370                         declaration_statement_t const *const decls = &stmt->declaration;
5371                         warn_unused_decl(decls->declarations_begin, decls->declarations_end,
5372                                          "variable");
5373                         return;
5374                 }
5375
5376                 case STATEMENT_FOR:
5377                         warn_unused_decl(stmt->fors.scope.entities, NULL, "variable");
5378                         return;
5379
5380                 default:
5381                         return;
5382         }
5383 }
5384
5385 /**
5386  * Check declarations of current_function for unused entities.
5387  */
5388 static void check_declarations(void)
5389 {
5390         if (warning.unused_parameter) {
5391                 const scope_t *scope = &current_function->parameters;
5392
5393                 /* do not issue unused warnings for main */
5394                 if (!is_sym_main(current_function->base.base.symbol)) {
5395                         warn_unused_decl(scope->entities, NULL, "parameter");
5396                 }
5397         }
5398         if (warning.unused_variable) {
5399                 walk_statements(current_function->statement, check_unused_variables,
5400                                 NULL);
5401         }
5402 }
5403
5404 static int determine_truth(expression_t const* const cond)
5405 {
5406         return
5407                 !is_constant_expression(cond) ? 0 :
5408                 fold_constant(cond) != 0      ? 1 :
5409                 -1;
5410 }
5411
5412 static bool expression_returns(expression_t const *const expr)
5413 {
5414         switch (expr->kind) {
5415                 case EXPR_CALL: {
5416                         expression_t const *const func = expr->call.function;
5417                         if (func->kind == EXPR_REFERENCE) {
5418                                 entity_t *entity = func->reference.entity;
5419                                 if (entity->kind == ENTITY_FUNCTION
5420                                                 && entity->declaration.modifiers & DM_NORETURN)
5421                                         return false;
5422                         }
5423
5424                         if (!expression_returns(func))
5425                                 return false;
5426
5427                         for (call_argument_t const* arg = expr->call.arguments; arg != NULL; arg = arg->next) {
5428                                 if (!expression_returns(arg->expression))
5429                                         return false;
5430                         }
5431
5432                         return true;
5433                 }
5434
5435                 case EXPR_REFERENCE:
5436                 case EXPR_REFERENCE_ENUM_VALUE:
5437                 case EXPR_CONST:
5438                 case EXPR_CHARACTER_CONSTANT:
5439                 case EXPR_WIDE_CHARACTER_CONSTANT:
5440                 case EXPR_STRING_LITERAL:
5441                 case EXPR_WIDE_STRING_LITERAL:
5442                 case EXPR_COMPOUND_LITERAL: // TODO descend into initialisers
5443                 case EXPR_LABEL_ADDRESS:
5444                 case EXPR_CLASSIFY_TYPE:
5445                 case EXPR_SIZEOF: // TODO handle obscure VLA case
5446                 case EXPR_ALIGNOF:
5447                 case EXPR_FUNCNAME:
5448                 case EXPR_BUILTIN_SYMBOL:
5449                 case EXPR_BUILTIN_CONSTANT_P:
5450                 case EXPR_BUILTIN_PREFETCH:
5451                 case EXPR_OFFSETOF:
5452                 case EXPR_INVALID:
5453                 case EXPR_STATEMENT: // TODO implement
5454                         return true;
5455
5456                 case EXPR_CONDITIONAL:
5457                         // TODO handle constant expression
5458                         return
5459                                 expression_returns(expr->conditional.condition) && (
5460                                         expression_returns(expr->conditional.true_expression) ||
5461                                         expression_returns(expr->conditional.false_expression)
5462                                 );
5463
5464                 case EXPR_SELECT:
5465                         return expression_returns(expr->select.compound);
5466
5467                 case EXPR_ARRAY_ACCESS:
5468                         return
5469                                 expression_returns(expr->array_access.array_ref) &&
5470                                 expression_returns(expr->array_access.index);
5471
5472                 case EXPR_VA_START:
5473                         return expression_returns(expr->va_starte.ap);
5474
5475                 case EXPR_VA_ARG:
5476                         return expression_returns(expr->va_arge.ap);
5477
5478                 EXPR_UNARY_CASES_MANDATORY
5479                         return expression_returns(expr->unary.value);
5480
5481                 case EXPR_UNARY_THROW:
5482                         return false;
5483
5484                 EXPR_BINARY_CASES
5485                         // TODO handle constant lhs of && and ||
5486                         return
5487                                 expression_returns(expr->binary.left) &&
5488                                 expression_returns(expr->binary.right);
5489
5490                 case EXPR_UNKNOWN:
5491                         break;
5492         }
5493
5494         panic("unhandled expression");
5495 }
5496
5497 static bool noreturn_candidate;
5498
5499 static void check_reachable(statement_t *const stmt)
5500 {
5501         if (stmt->base.reachable)
5502                 return;
5503         if (stmt->kind != STATEMENT_DO_WHILE)
5504                 stmt->base.reachable = true;
5505
5506         statement_t *last = stmt;
5507         statement_t *next;
5508         switch (stmt->kind) {
5509                 case STATEMENT_INVALID:
5510                 case STATEMENT_EMPTY:
5511                 case STATEMENT_DECLARATION:
5512                 case STATEMENT_LOCAL_LABEL:
5513                 case STATEMENT_ASM:
5514                         next = stmt->base.next;
5515                         break;
5516
5517                 case STATEMENT_COMPOUND:
5518                         next = stmt->compound.statements;
5519                         break;
5520
5521                 case STATEMENT_RETURN:
5522                         noreturn_candidate = false;
5523                         return;
5524
5525                 case STATEMENT_IF: {
5526                         if_statement_t const* const ifs = &stmt->ifs;
5527                         int            const        val = determine_truth(ifs->condition);
5528
5529                         if (val >= 0)
5530                                 check_reachable(ifs->true_statement);
5531
5532                         if (val > 0)
5533                                 return;
5534
5535                         if (ifs->false_statement != NULL) {
5536                                 check_reachable(ifs->false_statement);
5537                                 return;
5538                         }
5539
5540                         next = stmt->base.next;
5541                         break;
5542                 }
5543
5544                 case STATEMENT_SWITCH: {
5545                         switch_statement_t const *const switchs = &stmt->switchs;
5546                         expression_t       const *const expr    = switchs->expression;
5547
5548                         if (is_constant_expression(expr)) {
5549                                 long                    const val      = fold_constant(expr);
5550                                 case_label_statement_t *      defaults = NULL;
5551                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5552                                         if (i->expression == NULL) {
5553                                                 defaults = i;
5554                                                 continue;
5555                                         }
5556
5557                                         if (i->first_case <= val && val <= i->last_case) {
5558                                                 check_reachable((statement_t*)i);
5559                                                 return;
5560                                         }
5561                                 }
5562
5563                                 if (defaults != NULL) {
5564                                         check_reachable((statement_t*)defaults);
5565                                         return;
5566                                 }
5567                         } else {
5568                                 bool has_default = false;
5569                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5570                                         if (i->expression == NULL)
5571                                                 has_default = true;
5572
5573                                         check_reachable((statement_t*)i);
5574                                 }
5575
5576                                 if (has_default)
5577                                         return;
5578                         }
5579
5580                         next = stmt->base.next;
5581                         break;
5582                 }
5583
5584                 case STATEMENT_EXPRESSION: {
5585                         /* Check for noreturn function call */
5586                         expression_t const *const expr = stmt->expression.expression;
5587                         if (!expression_returns(expr))
5588                                 return;
5589
5590                         next = stmt->base.next;
5591                         break;
5592                 }
5593
5594                 case STATEMENT_CONTINUE: {
5595                         statement_t *parent = stmt;
5596                         for (;;) {
5597                                 parent = parent->base.parent;
5598                                 if (parent == NULL) /* continue not within loop */
5599                                         return;
5600
5601                                 next = parent;
5602                                 switch (parent->kind) {
5603                                         case STATEMENT_WHILE:    goto continue_while;
5604                                         case STATEMENT_DO_WHILE: goto continue_do_while;
5605                                         case STATEMENT_FOR:      goto continue_for;
5606
5607                                         default: break;
5608                                 }
5609                         }
5610                 }
5611
5612                 case STATEMENT_BREAK: {
5613                         statement_t *parent = stmt;
5614                         for (;;) {
5615                                 parent = parent->base.parent;
5616                                 if (parent == NULL) /* break not within loop/switch */
5617                                         return;
5618
5619                                 switch (parent->kind) {
5620                                         case STATEMENT_SWITCH:
5621                                         case STATEMENT_WHILE:
5622                                         case STATEMENT_DO_WHILE:
5623                                         case STATEMENT_FOR:
5624                                                 last = parent;
5625                                                 next = parent->base.next;
5626                                                 goto found_break_parent;
5627
5628                                         default: break;
5629                                 }
5630                         }
5631 found_break_parent:
5632                         break;
5633                 }
5634
5635                 case STATEMENT_GOTO:
5636                         if (stmt->gotos.expression) {
5637                                 statement_t *parent = stmt->base.parent;
5638                                 if (parent == NULL) /* top level goto */
5639                                         return;
5640                                 next = parent;
5641                         } else {
5642                                 next = stmt->gotos.label->statement;
5643                                 if (next == NULL) /* missing label */
5644                                         return;
5645                         }
5646                         break;
5647
5648                 case STATEMENT_LABEL:
5649                         next = stmt->label.statement;
5650                         break;
5651
5652                 case STATEMENT_CASE_LABEL:
5653                         next = stmt->case_label.statement;
5654                         break;
5655
5656                 case STATEMENT_WHILE: {
5657                         while_statement_t const *const whiles = &stmt->whiles;
5658                         int                      const val    = determine_truth(whiles->condition);
5659
5660                         if (val >= 0)
5661                                 check_reachable(whiles->body);
5662
5663                         if (val > 0)
5664                                 return;
5665
5666                         next = stmt->base.next;
5667                         break;
5668                 }
5669
5670                 case STATEMENT_DO_WHILE:
5671                         next = stmt->do_while.body;
5672                         break;
5673
5674                 case STATEMENT_FOR: {
5675                         for_statement_t *const fors = &stmt->fors;
5676
5677                         if (fors->condition_reachable)
5678                                 return;
5679                         fors->condition_reachable = true;
5680
5681                         expression_t const *const cond = fors->condition;
5682                         int          const        val  =
5683                                 cond == NULL ? 1 : determine_truth(cond);
5684
5685                         if (val >= 0)
5686                                 check_reachable(fors->body);
5687
5688                         if (val > 0)
5689                                 return;
5690
5691                         next = stmt->base.next;
5692                         break;
5693                 }
5694
5695                 case STATEMENT_MS_TRY: {
5696                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
5697                         check_reachable(ms_try->try_statement);
5698                         next = ms_try->final_statement;
5699                         break;
5700                 }
5701
5702                 case STATEMENT_LEAVE: {
5703                         statement_t *parent = stmt;
5704                         for (;;) {
5705                                 parent = parent->base.parent;
5706                                 if (parent == NULL) /* __leave not within __try */
5707                                         return;
5708
5709                                 if (parent->kind == STATEMENT_MS_TRY) {
5710                                         last = parent;
5711                                         next = parent->ms_try.final_statement;
5712                                         break;
5713                                 }
5714                         }
5715                         break;
5716                 }
5717         }
5718
5719         while (next == NULL) {
5720                 next = last->base.parent;
5721                 if (next == NULL) {
5722                         noreturn_candidate = false;
5723
5724                         type_t *const type = current_function->base.type;
5725                         assert(is_type_function(type));
5726                         type_t *const ret  = skip_typeref(type->function.return_type);
5727                         if (warning.return_type                    &&
5728                             !is_type_atomic(ret, ATOMIC_TYPE_VOID) &&
5729                             is_type_valid(ret)                     &&
5730                             !is_sym_main(current_function->base.base.symbol)) {
5731                                 warningf(&stmt->base.source_position,
5732                                          "control reaches end of non-void function");
5733                         }
5734                         return;
5735                 }
5736
5737                 switch (next->kind) {
5738                         case STATEMENT_INVALID:
5739                         case STATEMENT_EMPTY:
5740                         case STATEMENT_DECLARATION:
5741                         case STATEMENT_LOCAL_LABEL:
5742                         case STATEMENT_EXPRESSION:
5743                         case STATEMENT_ASM:
5744                         case STATEMENT_RETURN:
5745                         case STATEMENT_CONTINUE:
5746                         case STATEMENT_BREAK:
5747                         case STATEMENT_GOTO:
5748                         case STATEMENT_LEAVE:
5749                                 panic("invalid control flow in function");
5750
5751                         case STATEMENT_COMPOUND:
5752                         case STATEMENT_IF:
5753                         case STATEMENT_SWITCH:
5754                         case STATEMENT_LABEL:
5755                         case STATEMENT_CASE_LABEL:
5756                                 last = next;
5757                                 next = next->base.next;
5758                                 break;
5759
5760                         case STATEMENT_WHILE: {
5761 continue_while:
5762                                 if (next->base.reachable)
5763                                         return;
5764                                 next->base.reachable = true;
5765
5766                                 while_statement_t const *const whiles = &next->whiles;
5767                                 int                      const val    = determine_truth(whiles->condition);
5768
5769                                 if (val >= 0)
5770                                         check_reachable(whiles->body);
5771
5772                                 if (val > 0)
5773                                         return;
5774
5775                                 last = next;
5776                                 next = next->base.next;
5777                                 break;
5778                         }
5779
5780                         case STATEMENT_DO_WHILE: {
5781 continue_do_while:
5782                                 if (next->base.reachable)
5783                                         return;
5784                                 next->base.reachable = true;
5785
5786                                 do_while_statement_t const *const dw  = &next->do_while;
5787                                 int                  const        val = determine_truth(dw->condition);
5788
5789                                 if (val >= 0)
5790                                         check_reachable(dw->body);
5791
5792                                 if (val > 0)
5793                                         return;
5794
5795                                 last = next;
5796                                 next = next->base.next;
5797                                 break;
5798                         }
5799
5800                         case STATEMENT_FOR: {
5801 continue_for:;
5802                                 for_statement_t *const fors = &next->fors;
5803
5804                                 fors->step_reachable = true;
5805
5806                                 if (fors->condition_reachable)
5807                                         return;
5808                                 fors->condition_reachable = true;
5809
5810                                 expression_t const *const cond = fors->condition;
5811                                 int          const        val  =
5812                                         cond == NULL ? 1 : determine_truth(cond);
5813
5814                                 if (val >= 0)
5815                                         check_reachable(fors->body);
5816
5817                                 if (val > 0)
5818                                         return;
5819
5820                                 last = next;
5821                                 next = next->base.next;
5822                                 break;
5823                         }
5824
5825                         case STATEMENT_MS_TRY:
5826                                 last = next;
5827                                 next = next->ms_try.final_statement;
5828                                 break;
5829                 }
5830         }
5831
5832         check_reachable(next);
5833 }
5834
5835 static void check_unreachable(statement_t* const stmt, void *const env)
5836 {
5837         (void)env;
5838
5839         switch (stmt->kind) {
5840                 case STATEMENT_DO_WHILE:
5841                         if (!stmt->base.reachable) {
5842                                 expression_t const *const cond = stmt->do_while.condition;
5843                                 if (determine_truth(cond) >= 0) {
5844                                         warningf(&cond->base.source_position,
5845                                                  "condition of do-while-loop is unreachable");
5846                                 }
5847                         }
5848                         return;
5849
5850                 case STATEMENT_FOR: {
5851                         for_statement_t const* const fors = &stmt->fors;
5852
5853                         // if init and step are unreachable, cond is unreachable, too
5854                         if (!stmt->base.reachable && !fors->step_reachable) {
5855                                 warningf(&stmt->base.source_position, "statement is unreachable");
5856                         } else {
5857                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
5858                                         warningf(&fors->initialisation->base.source_position,
5859                                                  "initialisation of for-statement is unreachable");
5860                                 }
5861
5862                                 if (!fors->condition_reachable && fors->condition != NULL) {
5863                                         warningf(&fors->condition->base.source_position,
5864                                                  "condition of for-statement is unreachable");
5865                                 }
5866
5867                                 if (!fors->step_reachable && fors->step != NULL) {
5868                                         warningf(&fors->step->base.source_position,
5869                                                  "step of for-statement is unreachable");
5870                                 }
5871                         }
5872                         return;
5873                 }
5874
5875                 case STATEMENT_COMPOUND:
5876                         if (stmt->compound.statements != NULL)
5877                                 return;
5878                         /* FALLTHROUGH*/
5879
5880                 default:
5881                         if (!stmt->base.reachable)
5882                                 warningf(&stmt->base.source_position, "statement is unreachable");
5883                         return;
5884         }
5885 }
5886
5887 static void parse_external_declaration(void)
5888 {
5889         /* function-definitions and declarations both start with declaration
5890          * specifiers */
5891         declaration_specifiers_t specifiers;
5892         memset(&specifiers, 0, sizeof(specifiers));
5893
5894         add_anchor_token(';');
5895         parse_declaration_specifiers(&specifiers);
5896         rem_anchor_token(';');
5897
5898         /* must be a declaration */
5899         if (token.type == ';') {
5900                 parse_anonymous_declaration_rest(&specifiers);
5901                 return;
5902         }
5903
5904         add_anchor_token(',');
5905         add_anchor_token('=');
5906         add_anchor_token(';');
5907         add_anchor_token('{');
5908
5909         /* declarator is common to both function-definitions and declarations */
5910         entity_t *ndeclaration = parse_declarator(&specifiers, /*may_be_abstract=*/false, false);
5911
5912         rem_anchor_token('{');
5913         rem_anchor_token(';');
5914         rem_anchor_token('=');
5915         rem_anchor_token(',');
5916
5917         /* must be a declaration */
5918         switch (token.type) {
5919                 case ',':
5920                 case ';':
5921                 case '=':
5922                         parse_declaration_rest(ndeclaration, &specifiers, record_entity);
5923                         return;
5924         }
5925
5926         /* must be a function definition */
5927         parse_kr_declaration_list(ndeclaration);
5928
5929         if (token.type != '{') {
5930                 parse_error_expected("while parsing function definition", '{', NULL);
5931                 eat_until_matching_token(';');
5932                 return;
5933         }
5934
5935         assert(is_declaration(ndeclaration));
5936         type_t *type = skip_typeref(ndeclaration->declaration.type);
5937
5938         if (!is_type_function(type)) {
5939                 if (is_type_valid(type)) {
5940                         errorf(HERE, "declarator '%#T' has a body but is not a function type",
5941                                type, ndeclaration->base.symbol);
5942                 }
5943                 eat_block();
5944                 return;
5945         }
5946
5947         if (warning.aggregate_return &&
5948             is_type_compound(skip_typeref(type->function.return_type))) {
5949                 warningf(HERE, "function '%Y' returns an aggregate",
5950                          ndeclaration->base.symbol);
5951         }
5952         if (warning.traditional && !type->function.unspecified_parameters) {
5953                 warningf(HERE, "traditional C rejects ISO C style function definition of function '%Y'",
5954                         ndeclaration->base.symbol);
5955         }
5956         if (warning.old_style_definition && type->function.unspecified_parameters) {
5957                 warningf(HERE, "old-style function definition '%Y'",
5958                         ndeclaration->base.symbol);
5959         }
5960
5961         /* § 6.7.5.3 (14) a function definition with () means no
5962          * parameters (and not unspecified parameters) */
5963         if (type->function.unspecified_parameters
5964                         && type->function.parameters == NULL
5965                         && !type->function.kr_style_parameters) {
5966                 type_t *duplicate = duplicate_type(type);
5967                 duplicate->function.unspecified_parameters = false;
5968
5969                 type = typehash_insert(duplicate);
5970                 if (type != duplicate) {
5971                         obstack_free(type_obst, duplicate);
5972                 }
5973                 ndeclaration->declaration.type = type;
5974         }
5975
5976         entity_t *const entity = record_entity(ndeclaration, true);
5977         assert(entity->kind == ENTITY_FUNCTION);
5978         assert(ndeclaration->kind == ENTITY_FUNCTION);
5979
5980         function_t *function = &entity->function;
5981         if (ndeclaration != entity) {
5982                 function->parameters = ndeclaration->function.parameters;
5983         }
5984         assert(is_declaration(entity));
5985         type = skip_typeref(entity->declaration.type);
5986
5987         /* push function parameters and switch scope */
5988         size_t const top = environment_top();
5989         scope_push(&function->parameters);
5990
5991         entity_t *parameter = function->parameters.entities;
5992         for (; parameter != NULL; parameter = parameter->base.next) {
5993                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
5994                         parameter->base.parent_scope = current_scope;
5995                 }
5996                 assert(parameter->base.parent_scope == NULL
5997                                 || parameter->base.parent_scope == current_scope);
5998                 parameter->base.parent_scope = current_scope;
5999                 if (parameter->base.symbol == NULL) {
6000                         errorf(&parameter->base.source_position, "parameter name omitted");
6001                         continue;
6002                 }
6003                 environment_push(parameter);
6004         }
6005
6006         if (function->statement != NULL) {
6007                 parser_error_multiple_definition(entity, HERE);
6008                 eat_block();
6009         } else {
6010                 /* parse function body */
6011                 int         label_stack_top      = label_top();
6012                 function_t *old_current_function = current_function;
6013                 current_function                 = function;
6014                 current_parent                   = NULL;
6015
6016                 goto_first   = NULL;
6017                 goto_anchor  = &goto_first;
6018                 label_first  = NULL;
6019                 label_anchor = &label_first;
6020
6021                 statement_t *const body = parse_compound_statement(false);
6022                 function->statement = body;
6023                 first_err = true;
6024                 check_labels();
6025                 check_declarations();
6026                 if (warning.return_type      ||
6027                     warning.unreachable_code ||
6028                     (warning.missing_noreturn
6029                      && !(function->base.modifiers & DM_NORETURN))) {
6030                         noreturn_candidate = true;
6031                         check_reachable(body);
6032                         if (warning.unreachable_code)
6033                                 walk_statements(body, check_unreachable, NULL);
6034                         if (warning.missing_noreturn &&
6035                             noreturn_candidate       &&
6036                             !(function->base.modifiers & DM_NORETURN)) {
6037                                 warningf(&body->base.source_position,
6038                                          "function '%#T' is candidate for attribute 'noreturn'",
6039                                          type, entity->base.symbol);
6040                         }
6041                 }
6042
6043                 assert(current_parent   == NULL);
6044                 assert(current_function == function);
6045                 current_function = old_current_function;
6046                 label_pop_to(label_stack_top);
6047         }
6048
6049         assert(current_scope == &function->parameters);
6050         scope_pop();
6051         environment_pop_to(top);
6052 }
6053
6054 static type_t *make_bitfield_type(type_t *base_type, expression_t *size,
6055                                   source_position_t *source_position,
6056                                   const symbol_t *symbol)
6057 {
6058         type_t *type = allocate_type_zero(TYPE_BITFIELD);
6059
6060         type->bitfield.base_type       = base_type;
6061         type->bitfield.size_expression = size;
6062
6063         il_size_t bit_size;
6064         type_t *skipped_type = skip_typeref(base_type);
6065         if (!is_type_integer(skipped_type)) {
6066                 errorf(HERE, "bitfield base type '%T' is not an integer type",
6067                         base_type);
6068                 bit_size = 0;
6069         } else {
6070                 bit_size = skipped_type->base.size * 8;
6071         }
6072
6073         if (is_constant_expression(size)) {
6074                 long v = fold_constant(size);
6075
6076                 if (v < 0) {
6077                         errorf(source_position, "negative width in bit-field '%Y'", symbol);
6078                 } else if (v == 0) {
6079                         errorf(source_position, "zero width for bit-field '%Y'", symbol);
6080                 } else if (bit_size > 0 && (il_size_t)v > bit_size) {
6081                         errorf(source_position, "width of '%Y' exceeds its type", symbol);
6082                 } else {
6083                         type->bitfield.bit_size = v;
6084                 }
6085         }
6086
6087         return type;
6088 }
6089
6090 static entity_t *find_compound_entry(compound_t *compound, symbol_t *symbol)
6091 {
6092         entity_t *iter = compound->members.entities;
6093         for (; iter != NULL; iter = iter->base.next) {
6094                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
6095                         continue;
6096
6097                 if (iter->base.symbol == symbol) {
6098                         return iter;
6099                 } else if (iter->base.symbol == NULL) {
6100                         type_t *type = skip_typeref(iter->declaration.type);
6101                         if (is_type_compound(type)) {
6102                                 entity_t *result
6103                                         = find_compound_entry(type->compound.compound, symbol);
6104                                 if (result != NULL)
6105                                         return result;
6106                         }
6107                         continue;
6108                 }
6109         }
6110
6111         return NULL;
6112 }
6113
6114 static void parse_compound_declarators(compound_t *compound,
6115                 const declaration_specifiers_t *specifiers)
6116 {
6117         while (true) {
6118                 entity_t *entity;
6119
6120                 if (token.type == ':') {
6121                         source_position_t source_position = *HERE;
6122                         next_token();
6123
6124                         type_t *base_type = specifiers->type;
6125                         expression_t *size = parse_constant_expression();
6126
6127                         type_t *type = make_bitfield_type(base_type, size,
6128                                         &source_position, sym_anonymous);
6129
6130                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER);
6131                         entity->base.namespc                       = NAMESPACE_NORMAL;
6132                         entity->base.source_position               = source_position;
6133                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
6134                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
6135                         entity->declaration.modifiers              = specifiers->modifiers;
6136                         entity->declaration.type                   = type;
6137                 } else {
6138                         entity = parse_declarator(specifiers,/*may_be_abstract=*/true, true);
6139                         assert(entity->kind == ENTITY_COMPOUND_MEMBER);
6140
6141                         if (token.type == ':') {
6142                                 source_position_t source_position = *HERE;
6143                                 next_token();
6144                                 expression_t *size = parse_constant_expression();
6145
6146                                 type_t *type = entity->declaration.type;
6147                                 type_t *bitfield_type = make_bitfield_type(type, size,
6148                                                 &source_position, entity->base.symbol);
6149                                 entity->declaration.type = bitfield_type;
6150                         }
6151                 }
6152
6153                 /* make sure we don't define a symbol multiple times */
6154                 symbol_t *symbol = entity->base.symbol;
6155                 if (symbol != NULL) {
6156                         entity_t *prev = find_compound_entry(compound, symbol);
6157
6158                         if (prev != NULL) {
6159                                 errorf(&entity->base.source_position,
6160                                        "multiple declarations of symbol '%Y' (declared %P)",
6161                                        symbol, &prev->base.source_position);
6162                         }
6163                 }
6164
6165                 append_entity(&compound->members, entity);
6166
6167                 type_t *orig_type = entity->declaration.type;
6168                 type_t *type      = skip_typeref(orig_type);
6169                 if (is_type_function(type)) {
6170                         errorf(&entity->base.source_position,
6171                                         "compound member '%Y' must not have function type '%T'",
6172                                         entity->base.symbol, orig_type);
6173                 } else if (is_type_incomplete(type)) {
6174                         /* §6.7.2.1:16 flexible array member */
6175                         if (is_type_array(type) &&
6176                                         token.type == ';'   &&
6177                                         look_ahead(1)->type == '}') {
6178                                 compound->has_flexible_member = true;
6179                         } else {
6180                                 errorf(&entity->base.source_position,
6181                                                 "compound member '%Y' has incomplete type '%T'",
6182                                                 entity->base.symbol, orig_type);
6183                         }
6184                 }
6185
6186                 if (token.type != ',')
6187                         break;
6188                 next_token();
6189         }
6190         expect(';');
6191
6192 end_error:
6193         anonymous_entity = NULL;
6194 }
6195
6196 static void parse_compound_type_entries(compound_t *compound)
6197 {
6198         eat('{');
6199         add_anchor_token('}');
6200
6201         while (token.type != '}') {
6202                 if (token.type == T_EOF) {
6203                         errorf(HERE, "EOF while parsing struct");
6204                         break;
6205                 }
6206                 declaration_specifiers_t specifiers;
6207                 memset(&specifiers, 0, sizeof(specifiers));
6208                 parse_declaration_specifiers(&specifiers);
6209
6210                 parse_compound_declarators(compound, &specifiers);
6211         }
6212         rem_anchor_token('}');
6213         next_token();
6214
6215         /* §6.7.2.1:7 */
6216         compound->complete = true;
6217 }
6218
6219 static type_t *parse_typename(void)
6220 {
6221         declaration_specifiers_t specifiers;
6222         memset(&specifiers, 0, sizeof(specifiers));
6223         parse_declaration_specifiers(&specifiers);
6224         if (specifiers.storage_class != STORAGE_CLASS_NONE) {
6225                 /* TODO: improve error message, user does probably not know what a
6226                  * storage class is...
6227                  */
6228                 errorf(HERE, "typename may not have a storage class");
6229         }
6230
6231         type_t *result = parse_abstract_declarator(specifiers.type);
6232
6233         return result;
6234 }
6235
6236
6237
6238
6239 typedef expression_t* (*parse_expression_function)(void);
6240 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
6241
6242 typedef struct expression_parser_function_t expression_parser_function_t;
6243 struct expression_parser_function_t {
6244         parse_expression_function        parser;
6245         unsigned                         infix_precedence;
6246         parse_expression_infix_function  infix_parser;
6247 };
6248
6249 expression_parser_function_t expression_parsers[T_LAST_TOKEN];
6250
6251 /**
6252  * Prints an error message if an expression was expected but not read
6253  */
6254 static expression_t *expected_expression_error(void)
6255 {
6256         /* skip the error message if the error token was read */
6257         if (token.type != T_ERROR) {
6258                 errorf(HERE, "expected expression, got token '%K'", &token);
6259         }
6260         next_token();
6261
6262         return create_invalid_expression();
6263 }
6264
6265 /**
6266  * Parse a string constant.
6267  */
6268 static expression_t *parse_string_const(void)
6269 {
6270         wide_string_t wres;
6271         if (token.type == T_STRING_LITERAL) {
6272                 string_t res = token.v.string;
6273                 next_token();
6274                 while (token.type == T_STRING_LITERAL) {
6275                         res = concat_strings(&res, &token.v.string);
6276                         next_token();
6277                 }
6278                 if (token.type != T_WIDE_STRING_LITERAL) {
6279                         expression_t *const cnst = allocate_expression_zero(EXPR_STRING_LITERAL);
6280                         /* note: that we use type_char_ptr here, which is already the
6281                          * automatic converted type. revert_automatic_type_conversion
6282                          * will construct the array type */
6283                         cnst->base.type    = warning.write_strings ? type_const_char_ptr : type_char_ptr;
6284                         cnst->string.value = res;
6285                         return cnst;
6286                 }
6287
6288                 wres = concat_string_wide_string(&res, &token.v.wide_string);
6289         } else {
6290                 wres = token.v.wide_string;
6291         }
6292         next_token();
6293
6294         for (;;) {
6295                 switch (token.type) {
6296                         case T_WIDE_STRING_LITERAL:
6297                                 wres = concat_wide_strings(&wres, &token.v.wide_string);
6298                                 break;
6299
6300                         case T_STRING_LITERAL:
6301                                 wres = concat_wide_string_string(&wres, &token.v.string);
6302                                 break;
6303
6304                         default: {
6305                                 expression_t *const cnst = allocate_expression_zero(EXPR_WIDE_STRING_LITERAL);
6306                                 cnst->base.type         = warning.write_strings ? type_const_wchar_t_ptr : type_wchar_t_ptr;
6307                                 cnst->wide_string.value = wres;
6308                                 return cnst;
6309                         }
6310                 }
6311                 next_token();
6312         }
6313 }
6314
6315 /**
6316  * Parse a boolean constant.
6317  */
6318 static expression_t *parse_bool_const(bool value)
6319 {
6320         expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
6321         cnst->base.type          = type_bool;
6322         cnst->conste.v.int_value = value;
6323
6324         next_token();
6325
6326         return cnst;
6327 }
6328
6329 /**
6330  * Parse an integer constant.
6331  */
6332 static expression_t *parse_int_const(void)
6333 {
6334         expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
6335         cnst->base.type          = token.datatype;
6336         cnst->conste.v.int_value = token.v.intvalue;
6337
6338         next_token();
6339
6340         return cnst;
6341 }
6342
6343 /**
6344  * Parse a character constant.
6345  */
6346 static expression_t *parse_character_constant(void)
6347 {
6348         expression_t *cnst = allocate_expression_zero(EXPR_CHARACTER_CONSTANT);
6349         cnst->base.type          = token.datatype;
6350         cnst->conste.v.character = token.v.string;
6351
6352         if (cnst->conste.v.character.size != 1) {
6353                 if (!GNU_MODE) {
6354                         errorf(HERE, "more than 1 character in character constant");
6355                 } else if (warning.multichar) {
6356                         warningf(HERE, "multi-character character constant");
6357                 }
6358         }
6359         next_token();
6360
6361         return cnst;
6362 }
6363
6364 /**
6365  * Parse a wide character constant.
6366  */
6367 static expression_t *parse_wide_character_constant(void)
6368 {
6369         expression_t *cnst = allocate_expression_zero(EXPR_WIDE_CHARACTER_CONSTANT);
6370         cnst->base.type               = token.datatype;
6371         cnst->conste.v.wide_character = token.v.wide_string;
6372
6373         if (cnst->conste.v.wide_character.size != 1) {
6374                 if (!GNU_MODE) {
6375                         errorf(HERE, "more than 1 character in character constant");
6376                 } else if (warning.multichar) {
6377                         warningf(HERE, "multi-character character constant");
6378                 }
6379         }
6380         next_token();
6381
6382         return cnst;
6383 }
6384
6385 /**
6386  * Parse a float constant.
6387  */
6388 static expression_t *parse_float_const(void)
6389 {
6390         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
6391         cnst->base.type            = token.datatype;
6392         cnst->conste.v.float_value = token.v.floatvalue;
6393
6394         next_token();
6395
6396         return cnst;
6397 }
6398
6399 static entity_t *create_implicit_function(symbol_t *symbol,
6400                 const source_position_t *source_position)
6401 {
6402         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
6403         ntype->function.return_type            = type_int;
6404         ntype->function.unspecified_parameters = true;
6405
6406         type_t *type = typehash_insert(ntype);
6407         if (type != ntype) {
6408                 free_type(ntype);
6409         }
6410
6411         entity_t *entity = allocate_entity_zero(ENTITY_FUNCTION);
6412         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
6413         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
6414         entity->declaration.type                   = type;
6415         entity->declaration.implicit               = true;
6416         entity->base.symbol                        = symbol;
6417         entity->base.source_position               = *source_position;
6418
6419         bool strict_prototypes_old = warning.strict_prototypes;
6420         warning.strict_prototypes  = false;
6421         record_entity(entity, false);
6422         warning.strict_prototypes = strict_prototypes_old;
6423
6424         return entity;
6425 }
6426
6427 /**
6428  * Creates a return_type (func)(argument_type) function type if not
6429  * already exists.
6430  */
6431 static type_t *make_function_2_type(type_t *return_type, type_t *argument_type1,
6432                                     type_t *argument_type2)
6433 {
6434         function_parameter_t *parameter2
6435                 = obstack_alloc(type_obst, sizeof(parameter2[0]));
6436         memset(parameter2, 0, sizeof(parameter2[0]));
6437         parameter2->type = argument_type2;
6438
6439         function_parameter_t *parameter1
6440                 = obstack_alloc(type_obst, sizeof(parameter1[0]));
6441         memset(parameter1, 0, sizeof(parameter1[0]));
6442         parameter1->type = argument_type1;
6443         parameter1->next = parameter2;
6444
6445         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6446         type->function.return_type = return_type;
6447         type->function.parameters  = parameter1;
6448
6449         type_t *result = typehash_insert(type);
6450         if (result != type) {
6451                 free_type(type);
6452         }
6453
6454         return result;
6455 }
6456
6457 /**
6458  * Creates a return_type (func)(argument_type) function type if not
6459  * already exists.
6460  *
6461  * @param return_type    the return type
6462  * @param argument_type  the argument type
6463  */
6464 static type_t *make_function_1_type(type_t *return_type, type_t *argument_type)
6465 {
6466         function_parameter_t *parameter
6467                 = obstack_alloc(type_obst, sizeof(parameter[0]));
6468         memset(parameter, 0, sizeof(parameter[0]));
6469         parameter->type = argument_type;
6470
6471         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6472         type->function.return_type = return_type;
6473         type->function.parameters  = parameter;
6474
6475         type_t *result = typehash_insert(type);
6476         if (result != type) {
6477                 free_type(type);
6478         }
6479
6480         return result;
6481 }
6482
6483 static type_t *make_function_0_type(type_t *return_type)
6484 {
6485         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6486         type->function.return_type = return_type;
6487         type->function.parameters  = NULL;
6488
6489         type_t *result = typehash_insert(type);
6490         if (result != type) {
6491                 free_type(type);
6492         }
6493
6494         return result;
6495 }
6496
6497 /**
6498  * Creates a function type for some function like builtins.
6499  *
6500  * @param symbol   the symbol describing the builtin
6501  */
6502 static type_t *get_builtin_symbol_type(symbol_t *symbol)
6503 {
6504         switch (symbol->ID) {
6505         case T___builtin_alloca:
6506                 return make_function_1_type(type_void_ptr, type_size_t);
6507         case T___builtin_huge_val:
6508                 return make_function_0_type(type_double);
6509         case T___builtin_inf:
6510                 return make_function_0_type(type_double);
6511         case T___builtin_inff:
6512                 return make_function_0_type(type_float);
6513         case T___builtin_infl:
6514                 return make_function_0_type(type_long_double);
6515         case T___builtin_nan:
6516                 return make_function_1_type(type_double, type_char_ptr);
6517         case T___builtin_nanf:
6518                 return make_function_1_type(type_float, type_char_ptr);
6519         case T___builtin_nanl:
6520                 return make_function_1_type(type_long_double, type_char_ptr);
6521         case T___builtin_va_end:
6522                 return make_function_1_type(type_void, type_valist);
6523         case T___builtin_expect:
6524                 return make_function_2_type(type_long, type_long, type_long);
6525         default:
6526                 internal_errorf(HERE, "not implemented builtin symbol found");
6527         }
6528 }
6529
6530 /**
6531  * Performs automatic type cast as described in § 6.3.2.1.
6532  *
6533  * @param orig_type  the original type
6534  */
6535 static type_t *automatic_type_conversion(type_t *orig_type)
6536 {
6537         type_t *type = skip_typeref(orig_type);
6538         if (is_type_array(type)) {
6539                 array_type_t *array_type   = &type->array;
6540                 type_t       *element_type = array_type->element_type;
6541                 unsigned      qualifiers   = array_type->base.qualifiers;
6542
6543                 return make_pointer_type(element_type, qualifiers);
6544         }
6545
6546         if (is_type_function(type)) {
6547                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
6548         }
6549
6550         return orig_type;
6551 }
6552
6553 /**
6554  * reverts the automatic casts of array to pointer types and function
6555  * to function-pointer types as defined § 6.3.2.1
6556  */
6557 type_t *revert_automatic_type_conversion(const expression_t *expression)
6558 {
6559         switch (expression->kind) {
6560                 case EXPR_REFERENCE: {
6561                         entity_t *entity = expression->reference.entity;
6562                         if (is_declaration(entity)) {
6563                                 return entity->declaration.type;
6564                         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6565                                 return entity->enum_value.enum_type;
6566                         } else {
6567                                 panic("no declaration or enum in reference");
6568                         }
6569                 }
6570
6571                 case EXPR_SELECT: {
6572                         entity_t *entity = expression->select.compound_entry;
6573                         assert(is_declaration(entity));
6574                         type_t   *type   = entity->declaration.type;
6575                         return get_qualified_type(type,
6576                                                   expression->base.type->base.qualifiers);
6577                 }
6578
6579                 case EXPR_UNARY_DEREFERENCE: {
6580                         const expression_t *const value = expression->unary.value;
6581                         type_t             *const type  = skip_typeref(value->base.type);
6582                         assert(is_type_pointer(type));
6583                         return type->pointer.points_to;
6584                 }
6585
6586                 case EXPR_BUILTIN_SYMBOL:
6587                         return get_builtin_symbol_type(expression->builtin_symbol.symbol);
6588
6589                 case EXPR_ARRAY_ACCESS: {
6590                         const expression_t *array_ref = expression->array_access.array_ref;
6591                         type_t             *type_left = skip_typeref(array_ref->base.type);
6592                         if (!is_type_valid(type_left))
6593                                 return type_left;
6594                         assert(is_type_pointer(type_left));
6595                         return type_left->pointer.points_to;
6596                 }
6597
6598                 case EXPR_STRING_LITERAL: {
6599                         size_t size = expression->string.value.size;
6600                         return make_array_type(type_char, size, TYPE_QUALIFIER_NONE);
6601                 }
6602
6603                 case EXPR_WIDE_STRING_LITERAL: {
6604                         size_t size = expression->wide_string.value.size;
6605                         return make_array_type(type_wchar_t, size, TYPE_QUALIFIER_NONE);
6606                 }
6607
6608                 case EXPR_COMPOUND_LITERAL:
6609                         return expression->compound_literal.type;
6610
6611                 default: break;
6612         }
6613
6614         return expression->base.type;
6615 }
6616
6617 static expression_t *parse_reference(void)
6618 {
6619         symbol_t *const symbol = token.v.symbol;
6620
6621         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
6622
6623         if (entity == NULL) {
6624                 if (!strict_mode && look_ahead(1)->type == '(') {
6625                         /* an implicitly declared function */
6626                         if (warning.implicit_function_declaration) {
6627                                 warningf(HERE, "implicit declaration of function '%Y'",
6628                                         symbol);
6629                         }
6630
6631                         entity = create_implicit_function(symbol, HERE);
6632                 } else {
6633                         errorf(HERE, "unknown symbol '%Y' found.", symbol);
6634                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
6635                 }
6636         }
6637
6638         type_t *orig_type;
6639
6640         if (is_declaration(entity)) {
6641                 orig_type = entity->declaration.type;
6642         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6643                 orig_type = entity->enum_value.enum_type;
6644         } else if (entity->kind == ENTITY_TYPEDEF) {
6645                 errorf(HERE, "encountered typedef name '%Y' while parsing expression",
6646                         symbol);
6647                 next_token();
6648                 return create_invalid_expression();
6649         } else {
6650                 panic("expected declaration or enum value in reference");
6651         }
6652
6653         /* we always do the auto-type conversions; the & and sizeof parser contains
6654          * code to revert this! */
6655         type_t *type = automatic_type_conversion(orig_type);
6656
6657         expression_kind_t kind = EXPR_REFERENCE;
6658         if (entity->kind == ENTITY_ENUM_VALUE)
6659                 kind = EXPR_REFERENCE_ENUM_VALUE;
6660
6661         expression_t *expression     = allocate_expression_zero(kind);
6662         expression->reference.entity = entity;
6663         expression->base.type        = type;
6664
6665         /* this declaration is used */
6666         if (is_declaration(entity)) {
6667                 entity->declaration.used = true;
6668         }
6669
6670         if (entity->base.parent_scope != file_scope
6671                 && entity->base.parent_scope->depth < current_function->parameters.depth
6672                 && is_type_valid(orig_type) && !is_type_function(orig_type)) {
6673                 if (entity->kind == ENTITY_VARIABLE) {
6674                         /* access of a variable from an outer function */
6675                         entity->variable.address_taken = true;
6676                 }
6677                 current_function->need_closure = true;
6678         }
6679
6680         /* check for deprecated functions */
6681         if (warning.deprecated_declarations
6682                 && is_declaration(entity)
6683                 && entity->declaration.modifiers & DM_DEPRECATED) {
6684                 declaration_t *declaration = &entity->declaration;
6685
6686                 char const *const prefix = entity->kind == ENTITY_FUNCTION ?
6687                         "function" : "variable";
6688
6689                 if (declaration->deprecated_string != NULL) {
6690                         warningf(HERE, "%s '%Y' is deprecated (declared %P): \"%s\"",
6691                                  prefix, entity->base.symbol, &entity->base.source_position,
6692                                  declaration->deprecated_string);
6693                 } else {
6694                         warningf(HERE, "%s '%Y' is deprecated (declared %P)", prefix,
6695                                  entity->base.symbol, &entity->base.source_position);
6696                 }
6697         }
6698
6699         if (warning.init_self && entity == current_init_decl && !in_type_prop
6700             && entity->kind == ENTITY_VARIABLE) {
6701                 current_init_decl = NULL;
6702                 warningf(HERE, "variable '%#T' is initialized by itself",
6703                          entity->declaration.type, entity->base.symbol);
6704         }
6705
6706         next_token();
6707         return expression;
6708 }
6709
6710 static bool semantic_cast(expression_t *cast)
6711 {
6712         expression_t            *expression      = cast->unary.value;
6713         type_t                  *orig_dest_type  = cast->base.type;
6714         type_t                  *orig_type_right = expression->base.type;
6715         type_t            const *dst_type        = skip_typeref(orig_dest_type);
6716         type_t            const *src_type        = skip_typeref(orig_type_right);
6717         source_position_t const *pos             = &cast->base.source_position;
6718
6719         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation than for utility. */
6720         if (dst_type == type_void)
6721                 return true;
6722
6723         /* only integer and pointer can be casted to pointer */
6724         if (is_type_pointer(dst_type)  &&
6725             !is_type_pointer(src_type) &&
6726             !is_type_integer(src_type) &&
6727             is_type_valid(src_type)) {
6728                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
6729                 return false;
6730         }
6731
6732         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
6733                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
6734                 return false;
6735         }
6736
6737         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
6738                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
6739                 return false;
6740         }
6741
6742         if (warning.cast_qual &&
6743             is_type_pointer(src_type) &&
6744             is_type_pointer(dst_type)) {
6745                 type_t *src = skip_typeref(src_type->pointer.points_to);
6746                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
6747                 unsigned missing_qualifiers =
6748                         src->base.qualifiers & ~dst->base.qualifiers;
6749                 if (missing_qualifiers != 0) {
6750                         warningf(pos,
6751                                  "cast discards qualifiers '%Q' in pointer target type of '%T'",
6752                                  missing_qualifiers, orig_type_right);
6753                 }
6754         }
6755         return true;
6756 }
6757
6758 static expression_t *parse_compound_literal(type_t *type)
6759 {
6760         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
6761
6762         parse_initializer_env_t env;
6763         env.type             = type;
6764         env.entity           = NULL;
6765         env.must_be_constant = false;
6766         initializer_t *initializer = parse_initializer(&env);
6767         type = env.type;
6768
6769         expression->compound_literal.initializer = initializer;
6770         expression->compound_literal.type        = type;
6771         expression->base.type                    = automatic_type_conversion(type);
6772
6773         return expression;
6774 }
6775
6776 /**
6777  * Parse a cast expression.
6778  */
6779 static expression_t *parse_cast(void)
6780 {
6781         add_anchor_token(')');
6782
6783         source_position_t source_position = token.source_position;
6784
6785         type_t *type = parse_typename();
6786
6787         rem_anchor_token(')');
6788         expect(')');
6789
6790         if (token.type == '{') {
6791                 return parse_compound_literal(type);
6792         }
6793
6794         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
6795         cast->base.source_position = source_position;
6796
6797         expression_t *value = parse_sub_expression(PREC_CAST);
6798         cast->base.type   = type;
6799         cast->unary.value = value;
6800
6801         if (! semantic_cast(cast)) {
6802                 /* TODO: record the error in the AST. else it is impossible to detect it */
6803         }
6804
6805         return cast;
6806 end_error:
6807         return create_invalid_expression();
6808 }
6809
6810 /**
6811  * Parse a statement expression.
6812  */
6813 static expression_t *parse_statement_expression(void)
6814 {
6815         add_anchor_token(')');
6816
6817         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
6818
6819         statement_t *statement          = parse_compound_statement(true);
6820         expression->statement.statement = statement;
6821
6822         /* find last statement and use its type */
6823         type_t *type = type_void;
6824         const statement_t *stmt = statement->compound.statements;
6825         if (stmt != NULL) {
6826                 while (stmt->base.next != NULL)
6827                         stmt = stmt->base.next;
6828
6829                 if (stmt->kind == STATEMENT_EXPRESSION) {
6830                         type = stmt->expression.expression->base.type;
6831                 }
6832         } else if (warning.other) {
6833                 warningf(&expression->base.source_position, "empty statement expression ({})");
6834         }
6835         expression->base.type = type;
6836
6837         rem_anchor_token(')');
6838         expect(')');
6839
6840 end_error:
6841         return expression;
6842 }
6843
6844 /**
6845  * Parse a parenthesized expression.
6846  */
6847 static expression_t *parse_parenthesized_expression(void)
6848 {
6849         eat('(');
6850
6851         switch (token.type) {
6852         case '{':
6853                 /* gcc extension: a statement expression */
6854                 return parse_statement_expression();
6855
6856         TYPE_QUALIFIERS
6857         TYPE_SPECIFIERS
6858                 return parse_cast();
6859         case T_IDENTIFIER:
6860                 if (is_typedef_symbol(token.v.symbol)) {
6861                         return parse_cast();
6862                 }
6863         }
6864
6865         add_anchor_token(')');
6866         expression_t *result = parse_expression();
6867         rem_anchor_token(')');
6868         expect(')');
6869
6870 end_error:
6871         return result;
6872 }
6873
6874 static expression_t *parse_function_keyword(void)
6875 {
6876         /* TODO */
6877
6878         if (current_function == NULL) {
6879                 errorf(HERE, "'__func__' used outside of a function");
6880         }
6881
6882         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6883         expression->base.type     = type_char_ptr;
6884         expression->funcname.kind = FUNCNAME_FUNCTION;
6885
6886         next_token();
6887
6888         return expression;
6889 }
6890
6891 static expression_t *parse_pretty_function_keyword(void)
6892 {
6893         if (current_function == NULL) {
6894                 errorf(HERE, "'__PRETTY_FUNCTION__' used outside of a function");
6895         }
6896
6897         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6898         expression->base.type     = type_char_ptr;
6899         expression->funcname.kind = FUNCNAME_PRETTY_FUNCTION;
6900
6901         eat(T___PRETTY_FUNCTION__);
6902
6903         return expression;
6904 }
6905
6906 static expression_t *parse_funcsig_keyword(void)
6907 {
6908         if (current_function == NULL) {
6909                 errorf(HERE, "'__FUNCSIG__' used outside of a function");
6910         }
6911
6912         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6913         expression->base.type     = type_char_ptr;
6914         expression->funcname.kind = FUNCNAME_FUNCSIG;
6915
6916         eat(T___FUNCSIG__);
6917
6918         return expression;
6919 }
6920
6921 static expression_t *parse_funcdname_keyword(void)
6922 {
6923         if (current_function == NULL) {
6924                 errorf(HERE, "'__FUNCDNAME__' used outside of a function");
6925         }
6926
6927         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6928         expression->base.type     = type_char_ptr;
6929         expression->funcname.kind = FUNCNAME_FUNCDNAME;
6930
6931         eat(T___FUNCDNAME__);
6932
6933         return expression;
6934 }
6935
6936 static designator_t *parse_designator(void)
6937 {
6938         designator_t *result    = allocate_ast_zero(sizeof(result[0]));
6939         result->source_position = *HERE;
6940
6941         if (token.type != T_IDENTIFIER) {
6942                 parse_error_expected("while parsing member designator",
6943                                      T_IDENTIFIER, NULL);
6944                 return NULL;
6945         }
6946         result->symbol = token.v.symbol;
6947         next_token();
6948
6949         designator_t *last_designator = result;
6950         while (true) {
6951                 if (token.type == '.') {
6952                         next_token();
6953                         if (token.type != T_IDENTIFIER) {
6954                                 parse_error_expected("while parsing member designator",
6955                                                      T_IDENTIFIER, NULL);
6956                                 return NULL;
6957                         }
6958                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6959                         designator->source_position = *HERE;
6960                         designator->symbol          = token.v.symbol;
6961                         next_token();
6962
6963                         last_designator->next = designator;
6964                         last_designator       = designator;
6965                         continue;
6966                 }
6967                 if (token.type == '[') {
6968                         next_token();
6969                         add_anchor_token(']');
6970                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6971                         designator->source_position = *HERE;
6972                         designator->array_index     = parse_expression();
6973                         rem_anchor_token(']');
6974                         expect(']');
6975                         if (designator->array_index == NULL) {
6976                                 return NULL;
6977                         }
6978
6979                         last_designator->next = designator;
6980                         last_designator       = designator;
6981                         continue;
6982                 }
6983                 break;
6984         }
6985
6986         return result;
6987 end_error:
6988         return NULL;
6989 }
6990
6991 /**
6992  * Parse the __builtin_offsetof() expression.
6993  */
6994 static expression_t *parse_offsetof(void)
6995 {
6996         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
6997         expression->base.type    = type_size_t;
6998
6999         eat(T___builtin_offsetof);
7000
7001         expect('(');
7002         add_anchor_token(',');
7003         type_t *type = parse_typename();
7004         rem_anchor_token(',');
7005         expect(',');
7006         add_anchor_token(')');
7007         designator_t *designator = parse_designator();
7008         rem_anchor_token(')');
7009         expect(')');
7010
7011         expression->offsetofe.type       = type;
7012         expression->offsetofe.designator = designator;
7013
7014         type_path_t path;
7015         memset(&path, 0, sizeof(path));
7016         path.top_type = type;
7017         path.path     = NEW_ARR_F(type_path_entry_t, 0);
7018
7019         descend_into_subtype(&path);
7020
7021         if (!walk_designator(&path, designator, true)) {
7022                 return create_invalid_expression();
7023         }
7024
7025         DEL_ARR_F(path.path);
7026
7027         return expression;
7028 end_error:
7029         return create_invalid_expression();
7030 }
7031
7032 /**
7033  * Parses a _builtin_va_start() expression.
7034  */
7035 static expression_t *parse_va_start(void)
7036 {
7037         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
7038
7039         eat(T___builtin_va_start);
7040
7041         expect('(');
7042         add_anchor_token(',');
7043         expression->va_starte.ap = parse_assignment_expression();
7044         rem_anchor_token(',');
7045         expect(',');
7046         expression_t *const expr = parse_assignment_expression();
7047         if (expr->kind == EXPR_REFERENCE) {
7048                 entity_t *const entity = expr->reference.entity;
7049                 if (entity->base.parent_scope != &current_function->parameters
7050                                 || entity->base.next != NULL
7051                                 || entity->kind != ENTITY_VARIABLE) {
7052                         errorf(&expr->base.source_position,
7053                                "second argument of 'va_start' must be last parameter of the current function");
7054                 } else {
7055                         expression->va_starte.parameter = &entity->variable;
7056                 }
7057                 expect(')');
7058                 return expression;
7059         }
7060         expect(')');
7061 end_error:
7062         return create_invalid_expression();
7063 }
7064
7065 /**
7066  * Parses a _builtin_va_arg() expression.
7067  */
7068 static expression_t *parse_va_arg(void)
7069 {
7070         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
7071
7072         eat(T___builtin_va_arg);
7073
7074         expect('(');
7075         expression->va_arge.ap = parse_assignment_expression();
7076         expect(',');
7077         expression->base.type = parse_typename();
7078         expect(')');
7079
7080         return expression;
7081 end_error:
7082         return create_invalid_expression();
7083 }
7084
7085 static expression_t *parse_builtin_symbol(void)
7086 {
7087         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_SYMBOL);
7088
7089         symbol_t *symbol = token.v.symbol;
7090
7091         expression->builtin_symbol.symbol = symbol;
7092         next_token();
7093
7094         type_t *type = get_builtin_symbol_type(symbol);
7095         type = automatic_type_conversion(type);
7096
7097         expression->base.type = type;
7098         return expression;
7099 }
7100
7101 /**
7102  * Parses a __builtin_constant() expression.
7103  */
7104 static expression_t *parse_builtin_constant(void)
7105 {
7106         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
7107
7108         eat(T___builtin_constant_p);
7109
7110         expect('(');
7111         add_anchor_token(')');
7112         expression->builtin_constant.value = parse_assignment_expression();
7113         rem_anchor_token(')');
7114         expect(')');
7115         expression->base.type = type_int;
7116
7117         return expression;
7118 end_error:
7119         return create_invalid_expression();
7120 }
7121
7122 /**
7123  * Parses a __builtin_prefetch() expression.
7124  */
7125 static expression_t *parse_builtin_prefetch(void)
7126 {
7127         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_PREFETCH);
7128
7129         eat(T___builtin_prefetch);
7130
7131         expect('(');
7132         add_anchor_token(')');
7133         expression->builtin_prefetch.adr = parse_assignment_expression();
7134         if (token.type == ',') {
7135                 next_token();
7136                 expression->builtin_prefetch.rw = parse_assignment_expression();
7137         }
7138         if (token.type == ',') {
7139                 next_token();
7140                 expression->builtin_prefetch.locality = parse_assignment_expression();
7141         }
7142         rem_anchor_token(')');
7143         expect(')');
7144         expression->base.type = type_void;
7145
7146         return expression;
7147 end_error:
7148         return create_invalid_expression();
7149 }
7150
7151 /**
7152  * Parses a __builtin_is_*() compare expression.
7153  */
7154 static expression_t *parse_compare_builtin(void)
7155 {
7156         expression_t *expression;
7157
7158         switch (token.type) {
7159         case T___builtin_isgreater:
7160                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATER);
7161                 break;
7162         case T___builtin_isgreaterequal:
7163                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATEREQUAL);
7164                 break;
7165         case T___builtin_isless:
7166                 expression = allocate_expression_zero(EXPR_BINARY_ISLESS);
7167                 break;
7168         case T___builtin_islessequal:
7169                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSEQUAL);
7170                 break;
7171         case T___builtin_islessgreater:
7172                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSGREATER);
7173                 break;
7174         case T___builtin_isunordered:
7175                 expression = allocate_expression_zero(EXPR_BINARY_ISUNORDERED);
7176                 break;
7177         default:
7178                 internal_errorf(HERE, "invalid compare builtin found");
7179         }
7180         expression->base.source_position = *HERE;
7181         next_token();
7182
7183         expect('(');
7184         expression->binary.left = parse_assignment_expression();
7185         expect(',');
7186         expression->binary.right = parse_assignment_expression();
7187         expect(')');
7188
7189         type_t *const orig_type_left  = expression->binary.left->base.type;
7190         type_t *const orig_type_right = expression->binary.right->base.type;
7191
7192         type_t *const type_left  = skip_typeref(orig_type_left);
7193         type_t *const type_right = skip_typeref(orig_type_right);
7194         if (!is_type_float(type_left) && !is_type_float(type_right)) {
7195                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7196                         type_error_incompatible("invalid operands in comparison",
7197                                 &expression->base.source_position, orig_type_left, orig_type_right);
7198                 }
7199         } else {
7200                 semantic_comparison(&expression->binary);
7201         }
7202
7203         return expression;
7204 end_error:
7205         return create_invalid_expression();
7206 }
7207
7208 #if 0
7209 /**
7210  * Parses a __builtin_expect() expression.
7211  */
7212 static expression_t *parse_builtin_expect(void)
7213 {
7214         expression_t *expression
7215                 = allocate_expression_zero(EXPR_BINARY_BUILTIN_EXPECT);
7216
7217         eat(T___builtin_expect);
7218
7219         expect('(');
7220         expression->binary.left = parse_assignment_expression();
7221         expect(',');
7222         expression->binary.right = parse_constant_expression();
7223         expect(')');
7224
7225         expression->base.type = expression->binary.left->base.type;
7226
7227         return expression;
7228 end_error:
7229         return create_invalid_expression();
7230 }
7231 #endif
7232
7233 /**
7234  * Parses a MS assume() expression.
7235  */
7236 static expression_t *parse_assume(void)
7237 {
7238         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
7239
7240         eat(T__assume);
7241
7242         expect('(');
7243         add_anchor_token(')');
7244         expression->unary.value = parse_assignment_expression();
7245         rem_anchor_token(')');
7246         expect(')');
7247
7248         expression->base.type = type_void;
7249         return expression;
7250 end_error:
7251         return create_invalid_expression();
7252 }
7253
7254 /**
7255  * Return the declaration for a given label symbol or create a new one.
7256  *
7257  * @param symbol  the symbol of the label
7258  */
7259 static label_t *get_label(symbol_t *symbol)
7260 {
7261         entity_t *label;
7262         assert(current_function != NULL);
7263
7264         label = get_entity(symbol, NAMESPACE_LABEL);
7265         /* if we found a local label, we already created the declaration */
7266         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
7267                 if (label->base.parent_scope != current_scope) {
7268                         assert(label->base.parent_scope->depth < current_scope->depth);
7269                         current_function->goto_to_outer = true;
7270                 }
7271                 return &label->label;
7272         }
7273
7274         label = get_entity(symbol, NAMESPACE_LABEL);
7275         /* if we found a label in the same function, then we already created the
7276          * declaration */
7277         if (label != NULL
7278                         && label->base.parent_scope == &current_function->parameters) {
7279                 return &label->label;
7280         }
7281
7282         /* otherwise we need to create a new one */
7283         label               = allocate_entity_zero(ENTITY_LABEL);
7284         label->base.namespc = NAMESPACE_LABEL;
7285         label->base.symbol  = symbol;
7286
7287         label_push(label);
7288
7289         return &label->label;
7290 }
7291
7292 /**
7293  * Parses a GNU && label address expression.
7294  */
7295 static expression_t *parse_label_address(void)
7296 {
7297         source_position_t source_position = token.source_position;
7298         eat(T_ANDAND);
7299         if (token.type != T_IDENTIFIER) {
7300                 parse_error_expected("while parsing label address", T_IDENTIFIER, NULL);
7301                 goto end_error;
7302         }
7303         symbol_t *symbol = token.v.symbol;
7304         next_token();
7305
7306         label_t *label       = get_label(symbol);
7307         label->used          = true;
7308         label->address_taken = true;
7309
7310         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
7311         expression->base.source_position = source_position;
7312
7313         /* label address is threaten as a void pointer */
7314         expression->base.type           = type_void_ptr;
7315         expression->label_address.label = label;
7316         return expression;
7317 end_error:
7318         return create_invalid_expression();
7319 }
7320
7321 /**
7322  * Parse a microsoft __noop expression.
7323  */
7324 static expression_t *parse_noop_expression(void)
7325 {
7326         /* the result is a (int)0 */
7327         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
7328         cnst->base.type            = type_int;
7329         cnst->conste.v.int_value   = 0;
7330         cnst->conste.is_ms_noop    = true;
7331
7332         eat(T___noop);
7333
7334         if (token.type == '(') {
7335                 /* parse arguments */
7336                 eat('(');
7337                 add_anchor_token(')');
7338                 add_anchor_token(',');
7339
7340                 if (token.type != ')') {
7341                         while (true) {
7342                                 (void)parse_assignment_expression();
7343                                 if (token.type != ',')
7344                                         break;
7345                                 next_token();
7346                         }
7347                 }
7348         }
7349         rem_anchor_token(',');
7350         rem_anchor_token(')');
7351         expect(')');
7352
7353 end_error:
7354         return cnst;
7355 }
7356
7357 /**
7358  * Parses a primary expression.
7359  */
7360 static expression_t *parse_primary_expression(void)
7361 {
7362         switch (token.type) {
7363                 case T_false:                    return parse_bool_const(false);
7364                 case T_true:                     return parse_bool_const(true);
7365                 case T_INTEGER:                  return parse_int_const();
7366                 case T_CHARACTER_CONSTANT:       return parse_character_constant();
7367                 case T_WIDE_CHARACTER_CONSTANT:  return parse_wide_character_constant();
7368                 case T_FLOATINGPOINT:            return parse_float_const();
7369                 case T_STRING_LITERAL:
7370                 case T_WIDE_STRING_LITERAL:      return parse_string_const();
7371                 case T_IDENTIFIER:               return parse_reference();
7372                 case T___FUNCTION__:
7373                 case T___func__:                 return parse_function_keyword();
7374                 case T___PRETTY_FUNCTION__:      return parse_pretty_function_keyword();
7375                 case T___FUNCSIG__:              return parse_funcsig_keyword();
7376                 case T___FUNCDNAME__:            return parse_funcdname_keyword();
7377                 case T___builtin_offsetof:       return parse_offsetof();
7378                 case T___builtin_va_start:       return parse_va_start();
7379                 case T___builtin_va_arg:         return parse_va_arg();
7380                 case T___builtin_expect:
7381                 case T___builtin_alloca:
7382                 case T___builtin_inf:
7383                 case T___builtin_inff:
7384                 case T___builtin_infl:
7385                 case T___builtin_nan:
7386                 case T___builtin_nanf:
7387                 case T___builtin_nanl:
7388                 case T___builtin_huge_val:
7389                 case T___builtin_va_end:         return parse_builtin_symbol();
7390                 case T___builtin_isgreater:
7391                 case T___builtin_isgreaterequal:
7392                 case T___builtin_isless:
7393                 case T___builtin_islessequal:
7394                 case T___builtin_islessgreater:
7395                 case T___builtin_isunordered:    return parse_compare_builtin();
7396                 case T___builtin_constant_p:     return parse_builtin_constant();
7397                 case T___builtin_prefetch:       return parse_builtin_prefetch();
7398                 case T__assume:                  return parse_assume();
7399                 case T_ANDAND:
7400                         if (GNU_MODE)
7401                                 return parse_label_address();
7402                         break;
7403
7404                 case '(':                        return parse_parenthesized_expression();
7405                 case T___noop:                   return parse_noop_expression();
7406         }
7407
7408         errorf(HERE, "unexpected token %K, expected an expression", &token);
7409         return create_invalid_expression();
7410 }
7411
7412 /**
7413  * Check if the expression has the character type and issue a warning then.
7414  */
7415 static void check_for_char_index_type(const expression_t *expression)
7416 {
7417         type_t       *const type      = expression->base.type;
7418         const type_t *const base_type = skip_typeref(type);
7419
7420         if (is_type_atomic(base_type, ATOMIC_TYPE_CHAR) &&
7421                         warning.char_subscripts) {
7422                 warningf(&expression->base.source_position,
7423                          "array subscript has type '%T'", type);
7424         }
7425 }
7426
7427 static expression_t *parse_array_expression(expression_t *left)
7428 {
7429         expression_t *expression = allocate_expression_zero(EXPR_ARRAY_ACCESS);
7430
7431         eat('[');
7432         add_anchor_token(']');
7433
7434         expression_t *inside = parse_expression();
7435
7436         type_t *const orig_type_left   = left->base.type;
7437         type_t *const orig_type_inside = inside->base.type;
7438
7439         type_t *const type_left   = skip_typeref(orig_type_left);
7440         type_t *const type_inside = skip_typeref(orig_type_inside);
7441
7442         type_t                    *return_type;
7443         array_access_expression_t *array_access = &expression->array_access;
7444         if (is_type_pointer(type_left)) {
7445                 return_type             = type_left->pointer.points_to;
7446                 array_access->array_ref = left;
7447                 array_access->index     = inside;
7448                 check_for_char_index_type(inside);
7449         } else if (is_type_pointer(type_inside)) {
7450                 return_type             = type_inside->pointer.points_to;
7451                 array_access->array_ref = inside;
7452                 array_access->index     = left;
7453                 array_access->flipped   = true;
7454                 check_for_char_index_type(left);
7455         } else {
7456                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
7457                         errorf(HERE,
7458                                 "array access on object with non-pointer types '%T', '%T'",
7459                                 orig_type_left, orig_type_inside);
7460                 }
7461                 return_type             = type_error_type;
7462                 array_access->array_ref = left;
7463                 array_access->index     = inside;
7464         }
7465
7466         expression->base.type = automatic_type_conversion(return_type);
7467
7468         rem_anchor_token(']');
7469         expect(']');
7470 end_error:
7471         return expression;
7472 }
7473
7474 static expression_t *parse_typeprop(expression_kind_t const kind)
7475 {
7476         expression_t  *tp_expression = allocate_expression_zero(kind);
7477         tp_expression->base.type     = type_size_t;
7478
7479         eat(kind == EXPR_SIZEOF ? T_sizeof : T___alignof__);
7480
7481         /* we only refer to a type property, mark this case */
7482         bool old     = in_type_prop;
7483         in_type_prop = true;
7484
7485         type_t       *orig_type;
7486         expression_t *expression;
7487         if (token.type == '(' && is_declaration_specifier(look_ahead(1), true)) {
7488                 next_token();
7489                 add_anchor_token(')');
7490                 orig_type = parse_typename();
7491                 rem_anchor_token(')');
7492                 expect(')');
7493
7494                 if (token.type == '{') {
7495                         /* It was not sizeof(type) after all.  It is sizeof of an expression
7496                          * starting with a compound literal */
7497                         expression = parse_compound_literal(orig_type);
7498                         goto typeprop_expression;
7499                 }
7500         } else {
7501                 expression = parse_sub_expression(PREC_UNARY);
7502
7503 typeprop_expression:
7504                 tp_expression->typeprop.tp_expression = expression;
7505
7506                 orig_type = revert_automatic_type_conversion(expression);
7507                 expression->base.type = orig_type;
7508         }
7509
7510         tp_expression->typeprop.type   = orig_type;
7511         type_t const* const type       = skip_typeref(orig_type);
7512         char   const* const wrong_type =
7513                 is_type_incomplete(type)    ? "incomplete"          :
7514                 type->kind == TYPE_FUNCTION ? "function designator" :
7515                 type->kind == TYPE_BITFIELD ? "bitfield"            :
7516                 NULL;
7517         if (wrong_type != NULL) {
7518                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
7519                 errorf(&tp_expression->base.source_position,
7520                                 "operand of %s expression must not be of %s type '%T'",
7521                                 what, wrong_type, orig_type);
7522         }
7523
7524 end_error:
7525         in_type_prop = old;
7526         return tp_expression;
7527 }
7528
7529 static expression_t *parse_sizeof(void)
7530 {
7531         return parse_typeprop(EXPR_SIZEOF);
7532 }
7533
7534 static expression_t *parse_alignof(void)
7535 {
7536         return parse_typeprop(EXPR_ALIGNOF);
7537 }
7538
7539 static expression_t *parse_select_expression(expression_t *compound)
7540 {
7541         expression_t *select    = allocate_expression_zero(EXPR_SELECT);
7542         select->select.compound = compound;
7543
7544         assert(token.type == '.' || token.type == T_MINUSGREATER);
7545         bool is_pointer = (token.type == T_MINUSGREATER);
7546         next_token();
7547
7548         if (token.type != T_IDENTIFIER) {
7549                 parse_error_expected("while parsing select", T_IDENTIFIER, NULL);
7550                 return select;
7551         }
7552         symbol_t *symbol = token.v.symbol;
7553         next_token();
7554
7555         type_t *const orig_type = compound->base.type;
7556         type_t *const type      = skip_typeref(orig_type);
7557
7558         type_t *type_left;
7559         bool    saw_error = false;
7560         if (is_type_pointer(type)) {
7561                 if (!is_pointer) {
7562                         errorf(HERE,
7563                                "request for member '%Y' in something not a struct or union, but '%T'",
7564                                symbol, orig_type);
7565                         saw_error = true;
7566                 }
7567                 type_left = skip_typeref(type->pointer.points_to);
7568         } else {
7569                 if (is_pointer && is_type_valid(type)) {
7570                         errorf(HERE, "left hand side of '->' is not a pointer, but '%T'", orig_type);
7571                         saw_error = true;
7572                 }
7573                 type_left = type;
7574         }
7575
7576         entity_t *entry;
7577         if (type_left->kind == TYPE_COMPOUND_STRUCT ||
7578             type_left->kind == TYPE_COMPOUND_UNION) {
7579                 compound_t *compound = type_left->compound.compound;
7580
7581                 if (!compound->complete) {
7582                         errorf(HERE, "request for member '%Y' of incomplete type '%T'",
7583                                symbol, type_left);
7584                         goto create_error_entry;
7585                 }
7586
7587                 entry = find_compound_entry(compound, symbol);
7588                 if (entry == NULL) {
7589                         errorf(HERE, "'%T' has no member named '%Y'", orig_type, symbol);
7590                         goto create_error_entry;
7591                 }
7592         } else {
7593                 if (is_type_valid(type_left) && !saw_error) {
7594                         errorf(HERE,
7595                                "request for member '%Y' in something not a struct or union, but '%T'",
7596                                symbol, type_left);
7597                 }
7598 create_error_entry:
7599                 return create_invalid_expression();
7600         }
7601
7602         assert(is_declaration(entry));
7603         select->select.compound_entry = entry;
7604
7605         type_t *entry_type = entry->declaration.type;
7606         type_t *res_type
7607                 = get_qualified_type(entry_type, type_left->base.qualifiers);
7608
7609         /* we always do the auto-type conversions; the & and sizeof parser contains
7610          * code to revert this! */
7611         select->base.type = automatic_type_conversion(res_type);
7612
7613         type_t *skipped = skip_typeref(res_type);
7614         if (skipped->kind == TYPE_BITFIELD) {
7615                 select->base.type = skipped->bitfield.base_type;
7616         }
7617
7618         return select;
7619 }
7620
7621 static void check_call_argument(const function_parameter_t *parameter,
7622                                 call_argument_t *argument, unsigned pos)
7623 {
7624         type_t         *expected_type      = parameter->type;
7625         type_t         *expected_type_skip = skip_typeref(expected_type);
7626         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
7627         expression_t   *arg_expr           = argument->expression;
7628         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
7629
7630         /* handle transparent union gnu extension */
7631         if (is_type_union(expected_type_skip)
7632                         && (expected_type_skip->base.modifiers
7633                                 & TYPE_MODIFIER_TRANSPARENT_UNION)) {
7634                 compound_t *union_decl  = expected_type_skip->compound.compound;
7635                 type_t     *best_type   = NULL;
7636                 entity_t   *entry       = union_decl->members.entities;
7637                 for ( ; entry != NULL; entry = entry->base.next) {
7638                         assert(is_declaration(entry));
7639                         type_t *decl_type = entry->declaration.type;
7640                         error = semantic_assign(decl_type, arg_expr);
7641                         if (error == ASSIGN_ERROR_INCOMPATIBLE
7642                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
7643                                 continue;
7644
7645                         if (error == ASSIGN_SUCCESS) {
7646                                 best_type = decl_type;
7647                         } else if (best_type == NULL) {
7648                                 best_type = decl_type;
7649                         }
7650                 }
7651
7652                 if (best_type != NULL) {
7653                         expected_type = best_type;
7654                 }
7655         }
7656
7657         error                = semantic_assign(expected_type, arg_expr);
7658         argument->expression = create_implicit_cast(argument->expression,
7659                                                     expected_type);
7660
7661         if (error != ASSIGN_SUCCESS) {
7662                 /* report exact scope in error messages (like "in argument 3") */
7663                 char buf[64];
7664                 snprintf(buf, sizeof(buf), "call argument %u", pos);
7665                 report_assign_error(error, expected_type, arg_expr,     buf,
7666                                                         &arg_expr->base.source_position);
7667         } else if (warning.traditional || warning.conversion) {
7668                 type_t *const promoted_type = get_default_promoted_type(arg_type);
7669                 if (!types_compatible(expected_type_skip, promoted_type) &&
7670                     !types_compatible(expected_type_skip, type_void_ptr) &&
7671                     !types_compatible(type_void_ptr,      promoted_type)) {
7672                         /* Deliberately show the skipped types in this warning */
7673                         warningf(&arg_expr->base.source_position,
7674                                 "passing call argument %u as '%T' rather than '%T' due to prototype",
7675                                 pos, expected_type_skip, promoted_type);
7676                 }
7677         }
7678 }
7679
7680 /**
7681  * Parse a call expression, ie. expression '( ... )'.
7682  *
7683  * @param expression  the function address
7684  */
7685 static expression_t *parse_call_expression(expression_t *expression)
7686 {
7687         expression_t      *result = allocate_expression_zero(EXPR_CALL);
7688         call_expression_t *call   = &result->call;
7689         call->function            = expression;
7690
7691         type_t *const orig_type = expression->base.type;
7692         type_t *const type      = skip_typeref(orig_type);
7693
7694         function_type_t *function_type = NULL;
7695         if (is_type_pointer(type)) {
7696                 type_t *const to_type = skip_typeref(type->pointer.points_to);
7697
7698                 if (is_type_function(to_type)) {
7699                         function_type   = &to_type->function;
7700                         call->base.type = function_type->return_type;
7701                 }
7702         }
7703
7704         if (function_type == NULL && is_type_valid(type)) {
7705                 errorf(HERE, "called object '%E' (type '%T') is not a pointer to a function", expression, orig_type);
7706         }
7707
7708         /* parse arguments */
7709         eat('(');
7710         add_anchor_token(')');
7711         add_anchor_token(',');
7712
7713         if (token.type != ')') {
7714                 call_argument_t *last_argument = NULL;
7715
7716                 while (true) {
7717                         call_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
7718
7719                         argument->expression = parse_assignment_expression();
7720                         if (last_argument == NULL) {
7721                                 call->arguments = argument;
7722                         } else {
7723                                 last_argument->next = argument;
7724                         }
7725                         last_argument = argument;
7726
7727                         if (token.type != ',')
7728                                 break;
7729                         next_token();
7730                 }
7731         }
7732         rem_anchor_token(',');
7733         rem_anchor_token(')');
7734         expect(')');
7735
7736         if (function_type == NULL)
7737                 return result;
7738
7739         function_parameter_t *parameter = function_type->parameters;
7740         call_argument_t      *argument  = call->arguments;
7741         if (!function_type->unspecified_parameters) {
7742                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
7743                                 parameter = parameter->next, argument = argument->next) {
7744                         check_call_argument(parameter, argument, ++pos);
7745                 }
7746
7747                 if (parameter != NULL) {
7748                         errorf(HERE, "too few arguments to function '%E'", expression);
7749                 } else if (argument != NULL && !function_type->variadic) {
7750                         errorf(HERE, "too many arguments to function '%E'", expression);
7751                 }
7752         }
7753
7754         /* do default promotion */
7755         for (; argument != NULL; argument = argument->next) {
7756                 type_t *type = argument->expression->base.type;
7757
7758                 type = get_default_promoted_type(type);
7759
7760                 argument->expression
7761                         = create_implicit_cast(argument->expression, type);
7762         }
7763
7764         check_format(&result->call);
7765
7766         if (warning.aggregate_return &&
7767             is_type_compound(skip_typeref(function_type->return_type))) {
7768                 warningf(&result->base.source_position,
7769                          "function call has aggregate value");
7770         }
7771
7772 end_error:
7773         return result;
7774 }
7775
7776 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
7777
7778 static bool same_compound_type(const type_t *type1, const type_t *type2)
7779 {
7780         return
7781                 is_type_compound(type1) &&
7782                 type1->kind == type2->kind &&
7783                 type1->compound.compound == type2->compound.compound;
7784 }
7785
7786 static expression_t const *get_reference_address(expression_t const *expr)
7787 {
7788         bool regular_take_address = true;
7789         for (;;) {
7790                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7791                         expr = expr->unary.value;
7792                 } else {
7793                         regular_take_address = false;
7794                 }
7795
7796                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7797                         break;
7798
7799                 expr = expr->unary.value;
7800         }
7801
7802         if (expr->kind != EXPR_REFERENCE)
7803                 return NULL;
7804
7805         /* special case for functions which are automatically converted to a
7806          * pointer to function without an extra TAKE_ADDRESS operation */
7807         if (!regular_take_address &&
7808                         expr->reference.entity->kind != ENTITY_FUNCTION) {
7809                 return NULL;
7810         }
7811
7812         return expr;
7813 }
7814
7815 static void warn_reference_address_as_bool(expression_t const* expr)
7816 {
7817         if (!warning.address)
7818                 return;
7819
7820         expr = get_reference_address(expr);
7821         if (expr != NULL) {
7822                 warningf(&expr->base.source_position,
7823                          "the address of '%Y' will always evaluate as 'true'",
7824                          expr->reference.entity->base.symbol);
7825         }
7826 }
7827
7828 /**
7829  * Parse a conditional expression, ie. 'expression ? ... : ...'.
7830  *
7831  * @param expression  the conditional expression
7832  */
7833 static expression_t *parse_conditional_expression(expression_t *expression)
7834 {
7835         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
7836
7837         conditional_expression_t *conditional = &result->conditional;
7838         conditional->condition                = expression;
7839
7840         warn_reference_address_as_bool(expression);
7841
7842         eat('?');
7843         add_anchor_token(':');
7844
7845         /* 6.5.15.2 */
7846         type_t *const condition_type_orig = expression->base.type;
7847         type_t *const condition_type      = skip_typeref(condition_type_orig);
7848         if (!is_type_scalar(condition_type) && is_type_valid(condition_type)) {
7849                 type_error("expected a scalar type in conditional condition",
7850                            &expression->base.source_position, condition_type_orig);
7851         }
7852
7853         expression_t *true_expression = expression;
7854         bool          gnu_cond = false;
7855         if (GNU_MODE && token.type == ':') {
7856                 gnu_cond = true;
7857         } else {
7858                 true_expression = parse_expression();
7859         }
7860         rem_anchor_token(':');
7861         expect(':');
7862         expression_t *false_expression =
7863                 parse_sub_expression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
7864
7865         type_t *const orig_true_type  = true_expression->base.type;
7866         type_t *const orig_false_type = false_expression->base.type;
7867         type_t *const true_type       = skip_typeref(orig_true_type);
7868         type_t *const false_type      = skip_typeref(orig_false_type);
7869
7870         /* 6.5.15.3 */
7871         type_t *result_type;
7872         if (is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
7873                         is_type_atomic(false_type, ATOMIC_TYPE_VOID)) {
7874                 /* ISO/IEC 14882:1998(E) §5.16:2 */
7875                 if (true_expression->kind == EXPR_UNARY_THROW) {
7876                         result_type = false_type;
7877                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
7878                         result_type = true_type;
7879                 } else {
7880                         if (warning.other && (
7881                                                 !is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
7882                                                 !is_type_atomic(false_type, ATOMIC_TYPE_VOID)
7883                                         )) {
7884                                 warningf(&conditional->base.source_position,
7885                                                 "ISO C forbids conditional expression with only one void side");
7886                         }
7887                         result_type = type_void;
7888                 }
7889         } else if (is_type_arithmetic(true_type)
7890                    && is_type_arithmetic(false_type)) {
7891                 result_type = semantic_arithmetic(true_type, false_type);
7892
7893                 true_expression  = create_implicit_cast(true_expression, result_type);
7894                 false_expression = create_implicit_cast(false_expression, result_type);
7895
7896                 conditional->true_expression  = true_expression;
7897                 conditional->false_expression = false_expression;
7898                 conditional->base.type        = result_type;
7899         } else if (same_compound_type(true_type, false_type)) {
7900                 /* just take 1 of the 2 types */
7901                 result_type = true_type;
7902         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
7903                 type_t *pointer_type;
7904                 type_t *other_type;
7905                 expression_t *other_expression;
7906                 if (is_type_pointer(true_type) &&
7907                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
7908                         pointer_type     = true_type;
7909                         other_type       = false_type;
7910                         other_expression = false_expression;
7911                 } else {
7912                         pointer_type     = false_type;
7913                         other_type       = true_type;
7914                         other_expression = true_expression;
7915                 }
7916
7917                 if (is_null_pointer_constant(other_expression)) {
7918                         result_type = pointer_type;
7919                 } else if (is_type_pointer(other_type)) {
7920                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
7921                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
7922
7923                         type_t *to;
7924                         if (is_type_atomic(to1, ATOMIC_TYPE_VOID) ||
7925                             is_type_atomic(to2, ATOMIC_TYPE_VOID)) {
7926                                 to = type_void;
7927                         } else if (types_compatible(get_unqualified_type(to1),
7928                                                     get_unqualified_type(to2))) {
7929                                 to = to1;
7930                         } else {
7931                                 if (warning.other) {
7932                                         warningf(&conditional->base.source_position,
7933                                                         "pointer types '%T' and '%T' in conditional expression are incompatible",
7934                                                         true_type, false_type);
7935                                 }
7936                                 to = type_void;
7937                         }
7938
7939                         type_t *const type =
7940                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
7941                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
7942                 } else if (is_type_integer(other_type)) {
7943                         if (warning.other) {
7944                                 warningf(&conditional->base.source_position,
7945                                                 "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
7946                         }
7947                         result_type = pointer_type;
7948                 } else {
7949                         if (is_type_valid(other_type)) {
7950                                 type_error_incompatible("while parsing conditional",
7951                                                 &expression->base.source_position, true_type, false_type);
7952                         }
7953                         result_type = type_error_type;
7954                 }
7955         } else {
7956                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
7957                         type_error_incompatible("while parsing conditional",
7958                                                 &conditional->base.source_position, true_type,
7959                                                 false_type);
7960                 }
7961                 result_type = type_error_type;
7962         }
7963
7964         conditional->true_expression
7965                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
7966         conditional->false_expression
7967                 = create_implicit_cast(false_expression, result_type);
7968         conditional->base.type = result_type;
7969         return result;
7970 end_error:
7971         return create_invalid_expression();
7972 }
7973
7974 /**
7975  * Parse an extension expression.
7976  */
7977 static expression_t *parse_extension(void)
7978 {
7979         eat(T___extension__);
7980
7981         bool old_gcc_extension   = in_gcc_extension;
7982         in_gcc_extension         = true;
7983         expression_t *expression = parse_sub_expression(PREC_UNARY);
7984         in_gcc_extension         = old_gcc_extension;
7985         return expression;
7986 }
7987
7988 /**
7989  * Parse a __builtin_classify_type() expression.
7990  */
7991 static expression_t *parse_builtin_classify_type(void)
7992 {
7993         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
7994         result->base.type    = type_int;
7995
7996         eat(T___builtin_classify_type);
7997
7998         expect('(');
7999         add_anchor_token(')');
8000         expression_t *expression = parse_expression();
8001         rem_anchor_token(')');
8002         expect(')');
8003         result->classify_type.type_expression = expression;
8004
8005         return result;
8006 end_error:
8007         return create_invalid_expression();
8008 }
8009
8010 /**
8011  * Parse a delete expression
8012  * ISO/IEC 14882:1998(E) §5.3.5
8013  */
8014 static expression_t *parse_delete(void)
8015 {
8016         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
8017         result->base.type          = type_void;
8018
8019         eat(T_delete);
8020
8021         if (token.type == '[') {
8022                 next_token();
8023                 result->kind = EXPR_UNARY_DELETE_ARRAY;
8024                 expect(']');
8025 end_error:;
8026         }
8027
8028         expression_t *const value = parse_sub_expression(PREC_CAST);
8029         result->unary.value = value;
8030
8031         type_t *const type = skip_typeref(value->base.type);
8032         if (!is_type_pointer(type)) {
8033                 errorf(&value->base.source_position,
8034                                 "operand of delete must have pointer type");
8035         } else if (warning.other &&
8036                         is_type_atomic(skip_typeref(type->pointer.points_to), ATOMIC_TYPE_VOID)) {
8037                 warningf(&value->base.source_position,
8038                                 "deleting 'void*' is undefined");
8039         }
8040
8041         return result;
8042 }
8043
8044 /**
8045  * Parse a throw expression
8046  * ISO/IEC 14882:1998(E) §15:1
8047  */
8048 static expression_t *parse_throw(void)
8049 {
8050         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
8051         result->base.type          = type_void;
8052
8053         eat(T_throw);
8054
8055         expression_t *value = NULL;
8056         switch (token.type) {
8057                 EXPRESSION_START {
8058                         value = parse_assignment_expression();
8059                         /* ISO/IEC 14882:1998(E) §15.1:3 */
8060                         type_t *const orig_type = value->base.type;
8061                         type_t *const type      = skip_typeref(orig_type);
8062                         if (is_type_incomplete(type)) {
8063                                 errorf(&value->base.source_position,
8064                                                 "cannot throw object of incomplete type '%T'", orig_type);
8065                         } else if (is_type_pointer(type)) {
8066                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
8067                                 if (is_type_incomplete(points_to) &&
8068                                                 !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
8069                                         errorf(&value->base.source_position,
8070                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
8071                                 }
8072                         }
8073                 }
8074
8075                 default:
8076                         break;
8077         }
8078         result->unary.value = value;
8079
8080         return result;
8081 }
8082
8083 static bool check_pointer_arithmetic(const source_position_t *source_position,
8084                                      type_t *pointer_type,
8085                                      type_t *orig_pointer_type)
8086 {
8087         type_t *points_to = pointer_type->pointer.points_to;
8088         points_to = skip_typeref(points_to);
8089
8090         if (is_type_incomplete(points_to)) {
8091                 if (!GNU_MODE || !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
8092                         errorf(source_position,
8093                                "arithmetic with pointer to incomplete type '%T' not allowed",
8094                                orig_pointer_type);
8095                         return false;
8096                 } else if (warning.pointer_arith) {
8097                         warningf(source_position,
8098                                  "pointer of type '%T' used in arithmetic",
8099                                  orig_pointer_type);
8100                 }
8101         } else if (is_type_function(points_to)) {
8102                 if (!GNU_MODE) {
8103                         errorf(source_position,
8104                                "arithmetic with pointer to function type '%T' not allowed",
8105                                orig_pointer_type);
8106                         return false;
8107                 } else if (warning.pointer_arith) {
8108                         warningf(source_position,
8109                                  "pointer to a function '%T' used in arithmetic",
8110                                  orig_pointer_type);
8111                 }
8112         }
8113         return true;
8114 }
8115
8116 static bool is_lvalue(const expression_t *expression)
8117 {
8118         /* TODO: doesn't seem to be consistent with §6.3.2.1 (1) */
8119         switch (expression->kind) {
8120         case EXPR_REFERENCE:
8121         case EXPR_ARRAY_ACCESS:
8122         case EXPR_SELECT:
8123         case EXPR_UNARY_DEREFERENCE:
8124                 return true;
8125
8126         default:
8127                 /* Claim it is an lvalue, if the type is invalid.  There was a parse
8128                  * error before, which maybe prevented properly recognizing it as
8129                  * lvalue. */
8130                 return !is_type_valid(skip_typeref(expression->base.type));
8131         }
8132 }
8133
8134 static void semantic_incdec(unary_expression_t *expression)
8135 {
8136         type_t *const orig_type = expression->value->base.type;
8137         type_t *const type      = skip_typeref(orig_type);
8138         if (is_type_pointer(type)) {
8139                 if (!check_pointer_arithmetic(&expression->base.source_position,
8140                                               type, orig_type)) {
8141                         return;
8142                 }
8143         } else if (!is_type_real(type) && is_type_valid(type)) {
8144                 /* TODO: improve error message */
8145                 errorf(&expression->base.source_position,
8146                        "operation needs an arithmetic or pointer type");
8147                 return;
8148         }
8149         if (!is_lvalue(expression->value)) {
8150                 /* TODO: improve error message */
8151                 errorf(&expression->base.source_position, "lvalue required as operand");
8152         }
8153         expression->base.type = orig_type;
8154 }
8155
8156 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
8157 {
8158         type_t *const orig_type = expression->value->base.type;
8159         type_t *const type      = skip_typeref(orig_type);
8160         if (!is_type_arithmetic(type)) {
8161                 if (is_type_valid(type)) {
8162                         /* TODO: improve error message */
8163                         errorf(&expression->base.source_position,
8164                                 "operation needs an arithmetic type");
8165                 }
8166                 return;
8167         }
8168
8169         expression->base.type = orig_type;
8170 }
8171
8172 static void semantic_unexpr_plus(unary_expression_t *expression)
8173 {
8174         semantic_unexpr_arithmetic(expression);
8175         if (warning.traditional)
8176                 warningf(&expression->base.source_position,
8177                         "traditional C rejects the unary plus operator");
8178 }
8179
8180 static void semantic_not(unary_expression_t *expression)
8181 {
8182         type_t *const orig_type = expression->value->base.type;
8183         type_t *const type      = skip_typeref(orig_type);
8184         if (!is_type_scalar(type) && is_type_valid(type)) {
8185                 errorf(&expression->base.source_position,
8186                        "operand of ! must be of scalar type");
8187         }
8188
8189         warn_reference_address_as_bool(expression->value);
8190
8191         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8192 }
8193
8194 static void semantic_unexpr_integer(unary_expression_t *expression)
8195 {
8196         type_t *const orig_type = expression->value->base.type;
8197         type_t *const type      = skip_typeref(orig_type);
8198         if (!is_type_integer(type)) {
8199                 if (is_type_valid(type)) {
8200                         errorf(&expression->base.source_position,
8201                                "operand of ~ must be of integer type");
8202                 }
8203                 return;
8204         }
8205
8206         expression->base.type = orig_type;
8207 }
8208
8209 static void semantic_dereference(unary_expression_t *expression)
8210 {
8211         type_t *const orig_type = expression->value->base.type;
8212         type_t *const type      = skip_typeref(orig_type);
8213         if (!is_type_pointer(type)) {
8214                 if (is_type_valid(type)) {
8215                         errorf(&expression->base.source_position,
8216                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
8217                 }
8218                 return;
8219         }
8220
8221         type_t *result_type   = type->pointer.points_to;
8222         result_type           = automatic_type_conversion(result_type);
8223         expression->base.type = result_type;
8224 }
8225
8226 /**
8227  * Record that an address is taken (expression represents an lvalue).
8228  *
8229  * @param expression       the expression
8230  * @param may_be_register  if true, the expression might be an register
8231  */
8232 static void set_address_taken(expression_t *expression, bool may_be_register)
8233 {
8234         if (expression->kind != EXPR_REFERENCE)
8235                 return;
8236
8237         entity_t *const entity = expression->reference.entity;
8238
8239         if (entity->kind != ENTITY_VARIABLE)
8240                 return;
8241
8242         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
8243                         && !may_be_register) {
8244                 errorf(&expression->base.source_position,
8245                                 "address of register variable '%Y' requested",
8246                                 entity->base.symbol);
8247         }
8248
8249         entity->variable.address_taken = true;
8250 }
8251
8252 /**
8253  * Check the semantic of the address taken expression.
8254  */
8255 static void semantic_take_addr(unary_expression_t *expression)
8256 {
8257         expression_t *value = expression->value;
8258         value->base.type    = revert_automatic_type_conversion(value);
8259
8260         type_t *orig_type = value->base.type;
8261         type_t *type      = skip_typeref(orig_type);
8262         if (!is_type_valid(type))
8263                 return;
8264
8265         /* §6.5.3.2 */
8266         if (!is_lvalue(value)) {
8267                 errorf(&expression->base.source_position, "'&' requires an lvalue");
8268         }
8269         if (type->kind == TYPE_BITFIELD) {
8270                 errorf(&expression->base.source_position,
8271                        "'&' not allowed on object with bitfield type '%T'",
8272                        type);
8273         }
8274
8275         set_address_taken(value, false);
8276
8277         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
8278 }
8279
8280 #define CREATE_UNARY_EXPRESSION_PARSER(token_type, unexpression_type, sfunc) \
8281 static expression_t *parse_##unexpression_type(void)                         \
8282 {                                                                            \
8283         expression_t *unary_expression                                           \
8284                 = allocate_expression_zero(unexpression_type);                       \
8285         eat(token_type);                                                         \
8286         unary_expression->unary.value = parse_sub_expression(PREC_UNARY);        \
8287                                                                                  \
8288         sfunc(&unary_expression->unary);                                         \
8289                                                                                  \
8290         return unary_expression;                                                 \
8291 }
8292
8293 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
8294                                semantic_unexpr_arithmetic)
8295 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
8296                                semantic_unexpr_plus)
8297 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
8298                                semantic_not)
8299 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
8300                                semantic_dereference)
8301 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
8302                                semantic_take_addr)
8303 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
8304                                semantic_unexpr_integer)
8305 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
8306                                semantic_incdec)
8307 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
8308                                semantic_incdec)
8309
8310 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_type, unexpression_type, \
8311                                                sfunc)                         \
8312 static expression_t *parse_##unexpression_type(expression_t *left)            \
8313 {                                                                             \
8314         expression_t *unary_expression                                            \
8315                 = allocate_expression_zero(unexpression_type);                        \
8316         eat(token_type);                                                          \
8317         unary_expression->unary.value = left;                                     \
8318                                                                                   \
8319         sfunc(&unary_expression->unary);                                          \
8320                                                                               \
8321         return unary_expression;                                                  \
8322 }
8323
8324 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
8325                                        EXPR_UNARY_POSTFIX_INCREMENT,
8326                                        semantic_incdec)
8327 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
8328                                        EXPR_UNARY_POSTFIX_DECREMENT,
8329                                        semantic_incdec)
8330
8331 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
8332 {
8333         /* TODO: handle complex + imaginary types */
8334
8335         type_left  = get_unqualified_type(type_left);
8336         type_right = get_unqualified_type(type_right);
8337
8338         /* § 6.3.1.8 Usual arithmetic conversions */
8339         if (type_left == type_long_double || type_right == type_long_double) {
8340                 return type_long_double;
8341         } else if (type_left == type_double || type_right == type_double) {
8342                 return type_double;
8343         } else if (type_left == type_float || type_right == type_float) {
8344                 return type_float;
8345         }
8346
8347         type_left  = promote_integer(type_left);
8348         type_right = promote_integer(type_right);
8349
8350         if (type_left == type_right)
8351                 return type_left;
8352
8353         bool const signed_left  = is_type_signed(type_left);
8354         bool const signed_right = is_type_signed(type_right);
8355         int const  rank_left    = get_rank(type_left);
8356         int const  rank_right   = get_rank(type_right);
8357
8358         if (signed_left == signed_right)
8359                 return rank_left >= rank_right ? type_left : type_right;
8360
8361         int     s_rank;
8362         int     u_rank;
8363         type_t *s_type;
8364         type_t *u_type;
8365         if (signed_left) {
8366                 s_rank = rank_left;
8367                 s_type = type_left;
8368                 u_rank = rank_right;
8369                 u_type = type_right;
8370         } else {
8371                 s_rank = rank_right;
8372                 s_type = type_right;
8373                 u_rank = rank_left;
8374                 u_type = type_left;
8375         }
8376
8377         if (u_rank >= s_rank)
8378                 return u_type;
8379
8380         /* casting rank to atomic_type_kind is a bit hacky, but makes things
8381          * easier here... */
8382         if (get_atomic_type_size((atomic_type_kind_t) s_rank)
8383                         > get_atomic_type_size((atomic_type_kind_t) u_rank))
8384                 return s_type;
8385
8386         switch (s_rank) {
8387                 case ATOMIC_TYPE_INT:      return type_unsigned_int;
8388                 case ATOMIC_TYPE_LONG:     return type_unsigned_long;
8389                 case ATOMIC_TYPE_LONGLONG: return type_unsigned_long_long;
8390
8391                 default: panic("invalid atomic type");
8392         }
8393 }
8394
8395 /**
8396  * Check the semantic restrictions for a binary expression.
8397  */
8398 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
8399 {
8400         expression_t *const left            = expression->left;
8401         expression_t *const right           = expression->right;
8402         type_t       *const orig_type_left  = left->base.type;
8403         type_t       *const orig_type_right = right->base.type;
8404         type_t       *const type_left       = skip_typeref(orig_type_left);
8405         type_t       *const type_right      = skip_typeref(orig_type_right);
8406
8407         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8408                 /* TODO: improve error message */
8409                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8410                         errorf(&expression->base.source_position,
8411                                "operation needs arithmetic types");
8412                 }
8413                 return;
8414         }
8415
8416         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8417         expression->left      = create_implicit_cast(left, arithmetic_type);
8418         expression->right     = create_implicit_cast(right, arithmetic_type);
8419         expression->base.type = arithmetic_type;
8420 }
8421
8422 static void warn_div_by_zero(binary_expression_t const *const expression)
8423 {
8424         if (!warning.div_by_zero ||
8425             !is_type_integer(expression->base.type))
8426                 return;
8427
8428         expression_t const *const right = expression->right;
8429         /* The type of the right operand can be different for /= */
8430         if (is_type_integer(right->base.type) &&
8431             is_constant_expression(right)     &&
8432             fold_constant(right) == 0) {
8433                 warningf(&expression->base.source_position, "division by zero");
8434         }
8435 }
8436
8437 /**
8438  * Check the semantic restrictions for a div/mod expression.
8439  */
8440 static void semantic_divmod_arithmetic(binary_expression_t *expression) {
8441         semantic_binexpr_arithmetic(expression);
8442         warn_div_by_zero(expression);
8443 }
8444
8445 static void semantic_shift_op(binary_expression_t *expression)
8446 {
8447         expression_t *const left            = expression->left;
8448         expression_t *const right           = expression->right;
8449         type_t       *const orig_type_left  = left->base.type;
8450         type_t       *const orig_type_right = right->base.type;
8451         type_t       *      type_left       = skip_typeref(orig_type_left);
8452         type_t       *      type_right      = skip_typeref(orig_type_right);
8453
8454         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8455                 /* TODO: improve error message */
8456                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8457                         errorf(&expression->base.source_position,
8458                                "operands of shift operation must have integer types");
8459                 }
8460                 return;
8461         }
8462
8463         type_left  = promote_integer(type_left);
8464         type_right = promote_integer(type_right);
8465
8466         expression->left      = create_implicit_cast(left, type_left);
8467         expression->right     = create_implicit_cast(right, type_right);
8468         expression->base.type = type_left;
8469 }
8470
8471 static void semantic_add(binary_expression_t *expression)
8472 {
8473         expression_t *const left            = expression->left;
8474         expression_t *const right           = expression->right;
8475         type_t       *const orig_type_left  = left->base.type;
8476         type_t       *const orig_type_right = right->base.type;
8477         type_t       *const type_left       = skip_typeref(orig_type_left);
8478         type_t       *const type_right      = skip_typeref(orig_type_right);
8479
8480         /* § 6.5.6 */
8481         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8482                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8483                 expression->left  = create_implicit_cast(left, arithmetic_type);
8484                 expression->right = create_implicit_cast(right, arithmetic_type);
8485                 expression->base.type = arithmetic_type;
8486                 return;
8487         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8488                 check_pointer_arithmetic(&expression->base.source_position,
8489                                          type_left, orig_type_left);
8490                 expression->base.type = type_left;
8491         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
8492                 check_pointer_arithmetic(&expression->base.source_position,
8493                                          type_right, orig_type_right);
8494                 expression->base.type = type_right;
8495         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8496                 errorf(&expression->base.source_position,
8497                        "invalid operands to binary + ('%T', '%T')",
8498                        orig_type_left, orig_type_right);
8499         }
8500 }
8501
8502 static void semantic_sub(binary_expression_t *expression)
8503 {
8504         expression_t            *const left            = expression->left;
8505         expression_t            *const right           = expression->right;
8506         type_t                  *const orig_type_left  = left->base.type;
8507         type_t                  *const orig_type_right = right->base.type;
8508         type_t                  *const type_left       = skip_typeref(orig_type_left);
8509         type_t                  *const type_right      = skip_typeref(orig_type_right);
8510         source_position_t const *const pos             = &expression->base.source_position;
8511
8512         /* § 5.6.5 */
8513         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8514                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8515                 expression->left        = create_implicit_cast(left, arithmetic_type);
8516                 expression->right       = create_implicit_cast(right, arithmetic_type);
8517                 expression->base.type =  arithmetic_type;
8518                 return;
8519         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8520                 check_pointer_arithmetic(&expression->base.source_position,
8521                                          type_left, orig_type_left);
8522                 expression->base.type = type_left;
8523         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8524                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
8525                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
8526                 if (!types_compatible(unqual_left, unqual_right)) {
8527                         errorf(pos,
8528                                "subtracting pointers to incompatible types '%T' and '%T'",
8529                                orig_type_left, orig_type_right);
8530                 } else if (!is_type_object(unqual_left)) {
8531                         if (!is_type_atomic(unqual_left, ATOMIC_TYPE_VOID)) {
8532                                 errorf(pos, "subtracting pointers to non-object types '%T'",
8533                                        orig_type_left);
8534                         } else if (warning.other) {
8535                                 warningf(pos, "subtracting pointers to void");
8536                         }
8537                 }
8538                 expression->base.type = type_ptrdiff_t;
8539         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8540                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
8541                        orig_type_left, orig_type_right);
8542         }
8543 }
8544
8545 static void warn_string_literal_address(expression_t const* expr)
8546 {
8547         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
8548                 expr = expr->unary.value;
8549                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
8550                         return;
8551                 expr = expr->unary.value;
8552         }
8553
8554         if (expr->kind == EXPR_STRING_LITERAL ||
8555             expr->kind == EXPR_WIDE_STRING_LITERAL) {
8556                 warningf(&expr->base.source_position,
8557                         "comparison with string literal results in unspecified behaviour");
8558         }
8559 }
8560
8561 /**
8562  * Check the semantics of comparison expressions.
8563  *
8564  * @param expression   The expression to check.
8565  */
8566 static void semantic_comparison(binary_expression_t *expression)
8567 {
8568         expression_t *left  = expression->left;
8569         expression_t *right = expression->right;
8570
8571         if (warning.address) {
8572                 warn_string_literal_address(left);
8573                 warn_string_literal_address(right);
8574
8575                 expression_t const* const func_left = get_reference_address(left);
8576                 if (func_left != NULL && is_null_pointer_constant(right)) {
8577                         warningf(&expression->base.source_position,
8578                                  "the address of '%Y' will never be NULL",
8579                                  func_left->reference.entity->base.symbol);
8580                 }
8581
8582                 expression_t const* const func_right = get_reference_address(right);
8583                 if (func_right != NULL && is_null_pointer_constant(right)) {
8584                         warningf(&expression->base.source_position,
8585                                  "the address of '%Y' will never be NULL",
8586                                  func_right->reference.entity->base.symbol);
8587                 }
8588         }
8589
8590         type_t *orig_type_left  = left->base.type;
8591         type_t *orig_type_right = right->base.type;
8592         type_t *type_left       = skip_typeref(orig_type_left);
8593         type_t *type_right      = skip_typeref(orig_type_right);
8594
8595         /* TODO non-arithmetic types */
8596         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8597                 /* test for signed vs unsigned compares */
8598                 if (warning.sign_compare &&
8599                     (expression->base.kind != EXPR_BINARY_EQUAL &&
8600                      expression->base.kind != EXPR_BINARY_NOTEQUAL) &&
8601                     (is_type_signed(type_left) != is_type_signed(type_right))) {
8602
8603                         /* check if 1 of the operands is a constant, in this case we just
8604                          * check wether we can safely represent the resulting constant in
8605                          * the type of the other operand. */
8606                         expression_t *const_expr = NULL;
8607                         expression_t *other_expr = NULL;
8608
8609                         if (is_constant_expression(left)) {
8610                                 const_expr = left;
8611                                 other_expr = right;
8612                         } else if (is_constant_expression(right)) {
8613                                 const_expr = right;
8614                                 other_expr = left;
8615                         }
8616
8617                         if (const_expr != NULL) {
8618                                 type_t *other_type = skip_typeref(other_expr->base.type);
8619                                 long    val        = fold_constant(const_expr);
8620                                 /* TODO: check if val can be represented by other_type */
8621                                 (void) other_type;
8622                                 (void) val;
8623                         }
8624                         warningf(&expression->base.source_position,
8625                                  "comparison between signed and unsigned");
8626                 }
8627                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8628                 expression->left        = create_implicit_cast(left, arithmetic_type);
8629                 expression->right       = create_implicit_cast(right, arithmetic_type);
8630                 expression->base.type   = arithmetic_type;
8631                 if (warning.float_equal &&
8632                     (expression->base.kind == EXPR_BINARY_EQUAL ||
8633                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
8634                     is_type_float(arithmetic_type)) {
8635                         warningf(&expression->base.source_position,
8636                                  "comparing floating point with == or != is unsafe");
8637                 }
8638         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8639                 /* TODO check compatibility */
8640         } else if (is_type_pointer(type_left)) {
8641                 expression->right = create_implicit_cast(right, type_left);
8642         } else if (is_type_pointer(type_right)) {
8643                 expression->left = create_implicit_cast(left, type_right);
8644         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8645                 type_error_incompatible("invalid operands in comparison",
8646                                         &expression->base.source_position,
8647                                         type_left, type_right);
8648         }
8649         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8650 }
8651
8652 /**
8653  * Checks if a compound type has constant fields.
8654  */
8655 static bool has_const_fields(const compound_type_t *type)
8656 {
8657         compound_t *compound = type->compound;
8658         entity_t   *entry    = compound->members.entities;
8659
8660         for (; entry != NULL; entry = entry->base.next) {
8661                 if (!is_declaration(entry))
8662                         continue;
8663
8664                 const type_t *decl_type = skip_typeref(entry->declaration.type);
8665                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
8666                         return true;
8667         }
8668
8669         return false;
8670 }
8671
8672 static bool is_valid_assignment_lhs(expression_t const* const left)
8673 {
8674         type_t *const orig_type_left = revert_automatic_type_conversion(left);
8675         type_t *const type_left      = skip_typeref(orig_type_left);
8676
8677         if (!is_lvalue(left)) {
8678                 errorf(HERE, "left hand side '%E' of assignment is not an lvalue",
8679                        left);
8680                 return false;
8681         }
8682
8683         if (is_type_array(type_left)) {
8684                 errorf(HERE, "cannot assign to arrays ('%E')", left);
8685                 return false;
8686         }
8687         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
8688                 errorf(HERE, "assignment to readonly location '%E' (type '%T')", left,
8689                        orig_type_left);
8690                 return false;
8691         }
8692         if (is_type_incomplete(type_left)) {
8693                 errorf(HERE, "left-hand side '%E' of assignment has incomplete type '%T'",
8694                        left, orig_type_left);
8695                 return false;
8696         }
8697         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
8698                 errorf(HERE, "cannot assign to '%E' because compound type '%T' has readonly fields",
8699                        left, orig_type_left);
8700                 return false;
8701         }
8702
8703         return true;
8704 }
8705
8706 static void semantic_arithmetic_assign(binary_expression_t *expression)
8707 {
8708         expression_t *left            = expression->left;
8709         expression_t *right           = expression->right;
8710         type_t       *orig_type_left  = left->base.type;
8711         type_t       *orig_type_right = right->base.type;
8712
8713         if (!is_valid_assignment_lhs(left))
8714                 return;
8715
8716         type_t *type_left  = skip_typeref(orig_type_left);
8717         type_t *type_right = skip_typeref(orig_type_right);
8718
8719         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8720                 /* TODO: improve error message */
8721                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8722                         errorf(&expression->base.source_position,
8723                                "operation needs arithmetic types");
8724                 }
8725                 return;
8726         }
8727
8728         /* combined instructions are tricky. We can't create an implicit cast on
8729          * the left side, because we need the uncasted form for the store.
8730          * The ast2firm pass has to know that left_type must be right_type
8731          * for the arithmetic operation and create a cast by itself */
8732         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8733         expression->right       = create_implicit_cast(right, arithmetic_type);
8734         expression->base.type   = type_left;
8735 }
8736
8737 static void semantic_divmod_assign(binary_expression_t *expression)
8738 {
8739         semantic_arithmetic_assign(expression);
8740         warn_div_by_zero(expression);
8741 }
8742
8743 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
8744 {
8745         expression_t *const left            = expression->left;
8746         expression_t *const right           = expression->right;
8747         type_t       *const orig_type_left  = left->base.type;
8748         type_t       *const orig_type_right = right->base.type;
8749         type_t       *const type_left       = skip_typeref(orig_type_left);
8750         type_t       *const type_right      = skip_typeref(orig_type_right);
8751
8752         if (!is_valid_assignment_lhs(left))
8753                 return;
8754
8755         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8756                 /* combined instructions are tricky. We can't create an implicit cast on
8757                  * the left side, because we need the uncasted form for the store.
8758                  * The ast2firm pass has to know that left_type must be right_type
8759                  * for the arithmetic operation and create a cast by itself */
8760                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
8761                 expression->right     = create_implicit_cast(right, arithmetic_type);
8762                 expression->base.type = type_left;
8763         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8764                 check_pointer_arithmetic(&expression->base.source_position,
8765                                          type_left, orig_type_left);
8766                 expression->base.type = type_left;
8767         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8768                 errorf(&expression->base.source_position,
8769                        "incompatible types '%T' and '%T' in assignment",
8770                        orig_type_left, orig_type_right);
8771         }
8772 }
8773
8774 /**
8775  * Check the semantic restrictions of a logical expression.
8776  */
8777 static void semantic_logical_op(binary_expression_t *expression)
8778 {
8779         expression_t *const left            = expression->left;
8780         expression_t *const right           = expression->right;
8781         type_t       *const orig_type_left  = left->base.type;
8782         type_t       *const orig_type_right = right->base.type;
8783         type_t       *const type_left       = skip_typeref(orig_type_left);
8784         type_t       *const type_right      = skip_typeref(orig_type_right);
8785
8786         warn_reference_address_as_bool(left);
8787         warn_reference_address_as_bool(right);
8788
8789         if (!is_type_scalar(type_left) || !is_type_scalar(type_right)) {
8790                 /* TODO: improve error message */
8791                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8792                         errorf(&expression->base.source_position,
8793                                "operation needs scalar types");
8794                 }
8795                 return;
8796         }
8797
8798         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8799 }
8800
8801 /**
8802  * Check the semantic restrictions of a binary assign expression.
8803  */
8804 static void semantic_binexpr_assign(binary_expression_t *expression)
8805 {
8806         expression_t *left           = expression->left;
8807         type_t       *orig_type_left = left->base.type;
8808
8809         if (!is_valid_assignment_lhs(left))
8810                 return;
8811
8812         assign_error_t error = semantic_assign(orig_type_left, expression->right);
8813         report_assign_error(error, orig_type_left, expression->right,
8814                         "assignment", &left->base.source_position);
8815         expression->right = create_implicit_cast(expression->right, orig_type_left);
8816         expression->base.type = orig_type_left;
8817 }
8818
8819 /**
8820  * Determine if the outermost operation (or parts thereof) of the given
8821  * expression has no effect in order to generate a warning about this fact.
8822  * Therefore in some cases this only examines some of the operands of the
8823  * expression (see comments in the function and examples below).
8824  * Examples:
8825  *   f() + 23;    // warning, because + has no effect
8826  *   x || f();    // no warning, because x controls execution of f()
8827  *   x ? y : f(); // warning, because y has no effect
8828  *   (void)x;     // no warning to be able to suppress the warning
8829  * This function can NOT be used for an "expression has definitely no effect"-
8830  * analysis. */
8831 static bool expression_has_effect(const expression_t *const expr)
8832 {
8833         switch (expr->kind) {
8834                 case EXPR_UNKNOWN:                   break;
8835                 case EXPR_INVALID:                   return true; /* do NOT warn */
8836                 case EXPR_REFERENCE:                 return false;
8837                 case EXPR_REFERENCE_ENUM_VALUE:      return false;
8838                 /* suppress the warning for microsoft __noop operations */
8839                 case EXPR_CONST:                     return expr->conste.is_ms_noop;
8840                 case EXPR_CHARACTER_CONSTANT:        return false;
8841                 case EXPR_WIDE_CHARACTER_CONSTANT:   return false;
8842                 case EXPR_STRING_LITERAL:            return false;
8843                 case EXPR_WIDE_STRING_LITERAL:       return false;
8844                 case EXPR_LABEL_ADDRESS:             return false;
8845
8846                 case EXPR_CALL: {
8847                         const call_expression_t *const call = &expr->call;
8848                         if (call->function->kind != EXPR_BUILTIN_SYMBOL)
8849                                 return true;
8850
8851                         switch (call->function->builtin_symbol.symbol->ID) {
8852                                 case T___builtin_va_end: return true;
8853                                 default:                 return false;
8854                         }
8855                 }
8856
8857                 /* Generate the warning if either the left or right hand side of a
8858                  * conditional expression has no effect */
8859                 case EXPR_CONDITIONAL: {
8860                         const conditional_expression_t *const cond = &expr->conditional;
8861                         return
8862                                 expression_has_effect(cond->true_expression) &&
8863                                 expression_has_effect(cond->false_expression);
8864                 }
8865
8866                 case EXPR_SELECT:                    return false;
8867                 case EXPR_ARRAY_ACCESS:              return false;
8868                 case EXPR_SIZEOF:                    return false;
8869                 case EXPR_CLASSIFY_TYPE:             return false;
8870                 case EXPR_ALIGNOF:                   return false;
8871
8872                 case EXPR_FUNCNAME:                  return false;
8873                 case EXPR_BUILTIN_SYMBOL:            break; /* handled in EXPR_CALL */
8874                 case EXPR_BUILTIN_CONSTANT_P:        return false;
8875                 case EXPR_BUILTIN_PREFETCH:          return true;
8876                 case EXPR_OFFSETOF:                  return false;
8877                 case EXPR_VA_START:                  return true;
8878                 case EXPR_VA_ARG:                    return true;
8879                 case EXPR_STATEMENT:                 return true; // TODO
8880                 case EXPR_COMPOUND_LITERAL:          return false;
8881
8882                 case EXPR_UNARY_NEGATE:              return false;
8883                 case EXPR_UNARY_PLUS:                return false;
8884                 case EXPR_UNARY_BITWISE_NEGATE:      return false;
8885                 case EXPR_UNARY_NOT:                 return false;
8886                 case EXPR_UNARY_DEREFERENCE:         return false;
8887                 case EXPR_UNARY_TAKE_ADDRESS:        return false;
8888                 case EXPR_UNARY_POSTFIX_INCREMENT:   return true;
8889                 case EXPR_UNARY_POSTFIX_DECREMENT:   return true;
8890                 case EXPR_UNARY_PREFIX_INCREMENT:    return true;
8891                 case EXPR_UNARY_PREFIX_DECREMENT:    return true;
8892
8893                 /* Treat void casts as if they have an effect in order to being able to
8894                  * suppress the warning */
8895                 case EXPR_UNARY_CAST: {
8896                         type_t *const type = skip_typeref(expr->base.type);
8897                         return is_type_atomic(type, ATOMIC_TYPE_VOID);
8898                 }
8899
8900                 case EXPR_UNARY_CAST_IMPLICIT:       return true;
8901                 case EXPR_UNARY_ASSUME:              return true;
8902                 case EXPR_UNARY_DELETE:              return true;
8903                 case EXPR_UNARY_DELETE_ARRAY:        return true;
8904                 case EXPR_UNARY_THROW:               return true;
8905
8906                 case EXPR_BINARY_ADD:                return false;
8907                 case EXPR_BINARY_SUB:                return false;
8908                 case EXPR_BINARY_MUL:                return false;
8909                 case EXPR_BINARY_DIV:                return false;
8910                 case EXPR_BINARY_MOD:                return false;
8911                 case EXPR_BINARY_EQUAL:              return false;
8912                 case EXPR_BINARY_NOTEQUAL:           return false;
8913                 case EXPR_BINARY_LESS:               return false;
8914                 case EXPR_BINARY_LESSEQUAL:          return false;
8915                 case EXPR_BINARY_GREATER:            return false;
8916                 case EXPR_BINARY_GREATEREQUAL:       return false;
8917                 case EXPR_BINARY_BITWISE_AND:        return false;
8918                 case EXPR_BINARY_BITWISE_OR:         return false;
8919                 case EXPR_BINARY_BITWISE_XOR:        return false;
8920                 case EXPR_BINARY_SHIFTLEFT:          return false;
8921                 case EXPR_BINARY_SHIFTRIGHT:         return false;
8922                 case EXPR_BINARY_ASSIGN:             return true;
8923                 case EXPR_BINARY_MUL_ASSIGN:         return true;
8924                 case EXPR_BINARY_DIV_ASSIGN:         return true;
8925                 case EXPR_BINARY_MOD_ASSIGN:         return true;
8926                 case EXPR_BINARY_ADD_ASSIGN:         return true;
8927                 case EXPR_BINARY_SUB_ASSIGN:         return true;
8928                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:   return true;
8929                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:  return true;
8930                 case EXPR_BINARY_BITWISE_AND_ASSIGN: return true;
8931                 case EXPR_BINARY_BITWISE_XOR_ASSIGN: return true;
8932                 case EXPR_BINARY_BITWISE_OR_ASSIGN:  return true;
8933
8934                 /* Only examine the right hand side of && and ||, because the left hand
8935                  * side already has the effect of controlling the execution of the right
8936                  * hand side */
8937                 case EXPR_BINARY_LOGICAL_AND:
8938                 case EXPR_BINARY_LOGICAL_OR:
8939                 /* Only examine the right hand side of a comma expression, because the left
8940                  * hand side has a separate warning */
8941                 case EXPR_BINARY_COMMA:
8942                         return expression_has_effect(expr->binary.right);
8943
8944                 case EXPR_BINARY_BUILTIN_EXPECT:     return true;
8945                 case EXPR_BINARY_ISGREATER:          return false;
8946                 case EXPR_BINARY_ISGREATEREQUAL:     return false;
8947                 case EXPR_BINARY_ISLESS:             return false;
8948                 case EXPR_BINARY_ISLESSEQUAL:        return false;
8949                 case EXPR_BINARY_ISLESSGREATER:      return false;
8950                 case EXPR_BINARY_ISUNORDERED:        return false;
8951         }
8952
8953         internal_errorf(HERE, "unexpected expression");
8954 }
8955
8956 static void semantic_comma(binary_expression_t *expression)
8957 {
8958         if (warning.unused_value) {
8959                 const expression_t *const left = expression->left;
8960                 if (!expression_has_effect(left)) {
8961                         warningf(&left->base.source_position,
8962                                  "left-hand operand of comma expression has no effect");
8963                 }
8964         }
8965         expression->base.type = expression->right->base.type;
8966 }
8967
8968 /**
8969  * @param prec_r precedence of the right operand
8970  */
8971 #define CREATE_BINEXPR_PARSER(token_type, binexpression_type, prec_r, sfunc) \
8972 static expression_t *parse_##binexpression_type(expression_t *left)          \
8973 {                                                                            \
8974         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
8975         binexpr->binary.left  = left;                                            \
8976         eat(token_type);                                                         \
8977                                                                              \
8978         expression_t *right = parse_sub_expression(prec_r);                      \
8979                                                                              \
8980         binexpr->binary.right = right;                                           \
8981         sfunc(&binexpr->binary);                                                 \
8982                                                                              \
8983         return binexpr;                                                          \
8984 }
8985
8986 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
8987 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_divmod_arithmetic)
8988 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_divmod_arithmetic)
8989 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
8990 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
8991 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
8992 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
8993 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
8994 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
8995 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
8996 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
8997 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
8998 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
8999 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_arithmetic)
9000 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_arithmetic)
9001 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_arithmetic)
9002 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
9003 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
9004 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
9005 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
9006 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
9007 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9008 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
9009 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
9010 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9011 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9012 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9013 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9014 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9015 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
9016
9017
9018 static expression_t *parse_sub_expression(precedence_t precedence)
9019 {
9020         if (token.type < 0) {
9021                 return expected_expression_error();
9022         }
9023
9024         expression_parser_function_t *parser
9025                 = &expression_parsers[token.type];
9026         source_position_t             source_position = token.source_position;
9027         expression_t                 *left;
9028
9029         if (parser->parser != NULL) {
9030                 left = parser->parser();
9031         } else {
9032                 left = parse_primary_expression();
9033         }
9034         assert(left != NULL);
9035         left->base.source_position = source_position;
9036
9037         while (true) {
9038                 if (token.type < 0) {
9039                         return expected_expression_error();
9040                 }
9041
9042                 parser = &expression_parsers[token.type];
9043                 if (parser->infix_parser == NULL)
9044                         break;
9045                 if (parser->infix_precedence < precedence)
9046                         break;
9047
9048                 left = parser->infix_parser(left);
9049
9050                 assert(left != NULL);
9051                 assert(left->kind != EXPR_UNKNOWN);
9052                 left->base.source_position = source_position;
9053         }
9054
9055         return left;
9056 }
9057
9058 /**
9059  * Parse an expression.
9060  */
9061 static expression_t *parse_expression(void)
9062 {
9063         return parse_sub_expression(PREC_EXPRESSION);
9064 }
9065
9066 /**
9067  * Register a parser for a prefix-like operator.
9068  *
9069  * @param parser      the parser function
9070  * @param token_type  the token type of the prefix token
9071  */
9072 static void register_expression_parser(parse_expression_function parser,
9073                                        int token_type)
9074 {
9075         expression_parser_function_t *entry = &expression_parsers[token_type];
9076
9077         if (entry->parser != NULL) {
9078                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
9079                 panic("trying to register multiple expression parsers for a token");
9080         }
9081         entry->parser = parser;
9082 }
9083
9084 /**
9085  * Register a parser for an infix operator with given precedence.
9086  *
9087  * @param parser      the parser function
9088  * @param token_type  the token type of the infix operator
9089  * @param precedence  the precedence of the operator
9090  */
9091 static void register_infix_parser(parse_expression_infix_function parser,
9092                 int token_type, unsigned precedence)
9093 {
9094         expression_parser_function_t *entry = &expression_parsers[token_type];
9095
9096         if (entry->infix_parser != NULL) {
9097                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
9098                 panic("trying to register multiple infix expression parsers for a "
9099                       "token");
9100         }
9101         entry->infix_parser     = parser;
9102         entry->infix_precedence = precedence;
9103 }
9104
9105 /**
9106  * Initialize the expression parsers.
9107  */
9108 static void init_expression_parsers(void)
9109 {
9110         memset(&expression_parsers, 0, sizeof(expression_parsers));
9111
9112         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
9113         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
9114         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
9115         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
9116         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
9117         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
9118         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
9119         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
9120         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
9121         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
9122         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
9123         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
9124         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
9125         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
9126         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
9127         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
9128         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
9129         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
9130         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
9131         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
9132         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
9133         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
9134         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
9135         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
9136         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
9137         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
9138         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
9139         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
9140         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
9141         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
9142         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
9143         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
9144         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
9145         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
9146         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
9147         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
9148         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
9149
9150         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
9151         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
9152         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
9153         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~');
9154         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
9155         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
9156         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
9157         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
9158         register_expression_parser(parse_sizeof,                      T_sizeof);
9159         register_expression_parser(parse_alignof,                     T___alignof__);
9160         register_expression_parser(parse_extension,                   T___extension__);
9161         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
9162         register_expression_parser(parse_delete,                      T_delete);
9163         register_expression_parser(parse_throw,                       T_throw);
9164 }
9165
9166 /**
9167  * Parse a asm statement arguments specification.
9168  */
9169 static asm_argument_t *parse_asm_arguments(bool is_out)
9170 {
9171         asm_argument_t  *result = NULL;
9172         asm_argument_t **anchor = &result;
9173
9174         while (token.type == T_STRING_LITERAL || token.type == '[') {
9175                 asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
9176                 memset(argument, 0, sizeof(argument[0]));
9177
9178                 if (token.type == '[') {
9179                         eat('[');
9180                         if (token.type != T_IDENTIFIER) {
9181                                 parse_error_expected("while parsing asm argument",
9182                                                      T_IDENTIFIER, NULL);
9183                                 return NULL;
9184                         }
9185                         argument->symbol = token.v.symbol;
9186
9187                         expect(']');
9188                 }
9189
9190                 argument->constraints = parse_string_literals();
9191                 expect('(');
9192                 add_anchor_token(')');
9193                 expression_t *expression = parse_expression();
9194                 rem_anchor_token(')');
9195                 if (is_out) {
9196                         /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
9197                          * change size or type representation (e.g. int -> long is ok, but
9198                          * int -> float is not) */
9199                         if (expression->kind == EXPR_UNARY_CAST) {
9200                                 type_t      *const type = expression->base.type;
9201                                 type_kind_t  const kind = type->kind;
9202                                 if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
9203                                         unsigned flags;
9204                                         unsigned size;
9205                                         if (kind == TYPE_ATOMIC) {
9206                                                 atomic_type_kind_t const akind = type->atomic.akind;
9207                                                 flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
9208                                                 size  = get_atomic_type_size(akind);
9209                                         } else {
9210                                                 flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
9211                                                 size  = get_atomic_type_size(get_intptr_kind());
9212                                         }
9213
9214                                         do {
9215                                                 expression_t *const value      = expression->unary.value;
9216                                                 type_t       *const value_type = value->base.type;
9217                                                 type_kind_t   const value_kind = value_type->kind;
9218
9219                                                 unsigned value_flags;
9220                                                 unsigned value_size;
9221                                                 if (value_kind == TYPE_ATOMIC) {
9222                                                         atomic_type_kind_t const value_akind = value_type->atomic.akind;
9223                                                         value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
9224                                                         value_size  = get_atomic_type_size(value_akind);
9225                                                 } else if (value_kind == TYPE_POINTER) {
9226                                                         value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
9227                                                         value_size  = get_atomic_type_size(get_intptr_kind());
9228                                                 } else {
9229                                                         break;
9230                                                 }
9231
9232                                                 if (value_flags != flags || value_size != size)
9233                                                         break;
9234
9235                                                 expression = value;
9236                                         } while (expression->kind == EXPR_UNARY_CAST);
9237                                 }
9238                         }
9239
9240                         if (!is_lvalue(expression)) {
9241                                 errorf(&expression->base.source_position,
9242                                        "asm output argument is not an lvalue");
9243                         }
9244
9245                         if (argument->constraints.begin[0] == '+')
9246                                 mark_vars_read(expression, NULL);
9247                 } else {
9248                         mark_vars_read(expression, NULL);
9249                 }
9250                 argument->expression = expression;
9251                 expect(')');
9252
9253                 set_address_taken(expression, true);
9254
9255                 *anchor = argument;
9256                 anchor  = &argument->next;
9257
9258                 if (token.type != ',')
9259                         break;
9260                 eat(',');
9261         }
9262
9263         return result;
9264 end_error:
9265         return NULL;
9266 }
9267
9268 /**
9269  * Parse a asm statement clobber specification.
9270  */
9271 static asm_clobber_t *parse_asm_clobbers(void)
9272 {
9273         asm_clobber_t *result = NULL;
9274         asm_clobber_t *last   = NULL;
9275
9276         while (token.type == T_STRING_LITERAL) {
9277                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
9278                 clobber->clobber       = parse_string_literals();
9279
9280                 if (last != NULL) {
9281                         last->next = clobber;
9282                 } else {
9283                         result = clobber;
9284                 }
9285                 last = clobber;
9286
9287                 if (token.type != ',')
9288                         break;
9289                 eat(',');
9290         }
9291
9292         return result;
9293 }
9294
9295 /**
9296  * Parse an asm statement.
9297  */
9298 static statement_t *parse_asm_statement(void)
9299 {
9300         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
9301         asm_statement_t *asm_statement = &statement->asms;
9302
9303         eat(T_asm);
9304
9305         if (token.type == T_volatile) {
9306                 next_token();
9307                 asm_statement->is_volatile = true;
9308         }
9309
9310         expect('(');
9311         add_anchor_token(')');
9312         add_anchor_token(':');
9313         asm_statement->asm_text = parse_string_literals();
9314
9315         if (token.type != ':') {
9316                 rem_anchor_token(':');
9317                 goto end_of_asm;
9318         }
9319         eat(':');
9320
9321         asm_statement->outputs = parse_asm_arguments(true);
9322         if (token.type != ':') {
9323                 rem_anchor_token(':');
9324                 goto end_of_asm;
9325         }
9326         eat(':');
9327
9328         asm_statement->inputs = parse_asm_arguments(false);
9329         if (token.type != ':') {
9330                 rem_anchor_token(':');
9331                 goto end_of_asm;
9332         }
9333         rem_anchor_token(':');
9334         eat(':');
9335
9336         asm_statement->clobbers = parse_asm_clobbers();
9337
9338 end_of_asm:
9339         rem_anchor_token(')');
9340         expect(')');
9341         expect(';');
9342
9343         if (asm_statement->outputs == NULL) {
9344                 /* GCC: An 'asm' instruction without any output operands will be treated
9345                  * identically to a volatile 'asm' instruction. */
9346                 asm_statement->is_volatile = true;
9347         }
9348
9349         return statement;
9350 end_error:
9351         return create_invalid_statement();
9352 }
9353
9354 /**
9355  * Parse a case statement.
9356  */
9357 static statement_t *parse_case_statement(void)
9358 {
9359         statement_t       *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9360         source_position_t *const pos       = &statement->base.source_position;
9361
9362         eat(T_case);
9363
9364         expression_t *const expression   = parse_expression();
9365         statement->case_label.expression = expression;
9366         if (!is_constant_expression(expression)) {
9367                 /* This check does not prevent the error message in all cases of an
9368                  * prior error while parsing the expression.  At least it catches the
9369                  * common case of a mistyped enum entry. */
9370                 if (is_type_valid(skip_typeref(expression->base.type))) {
9371                         errorf(pos, "case label does not reduce to an integer constant");
9372                 }
9373                 statement->case_label.is_bad = true;
9374         } else {
9375                 long const val = fold_constant(expression);
9376                 statement->case_label.first_case = val;
9377                 statement->case_label.last_case  = val;
9378         }
9379
9380         if (GNU_MODE) {
9381                 if (token.type == T_DOTDOTDOT) {
9382                         next_token();
9383                         expression_t *const end_range   = parse_expression();
9384                         statement->case_label.end_range = end_range;
9385                         if (!is_constant_expression(end_range)) {
9386                                 /* This check does not prevent the error message in all cases of an
9387                                  * prior error while parsing the expression.  At least it catches the
9388                                  * common case of a mistyped enum entry. */
9389                                 if (is_type_valid(skip_typeref(end_range->base.type))) {
9390                                         errorf(pos, "case range does not reduce to an integer constant");
9391                                 }
9392                                 statement->case_label.is_bad = true;
9393                         } else {
9394                                 long const val = fold_constant(end_range);
9395                                 statement->case_label.last_case = val;
9396
9397                                 if (warning.other && val < statement->case_label.first_case) {
9398                                         statement->case_label.is_empty_range = true;
9399                                         warningf(pos, "empty range specified");
9400                                 }
9401                         }
9402                 }
9403         }
9404
9405         PUSH_PARENT(statement);
9406
9407         expect(':');
9408
9409         if (current_switch != NULL) {
9410                 if (! statement->case_label.is_bad) {
9411                         /* Check for duplicate case values */
9412                         case_label_statement_t *c = &statement->case_label;
9413                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
9414                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
9415                                         continue;
9416
9417                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
9418                                         continue;
9419
9420                                 errorf(pos, "duplicate case value (previously used %P)",
9421                                        &l->base.source_position);
9422                                 break;
9423                         }
9424                 }
9425                 /* link all cases into the switch statement */
9426                 if (current_switch->last_case == NULL) {
9427                         current_switch->first_case      = &statement->case_label;
9428                 } else {
9429                         current_switch->last_case->next = &statement->case_label;
9430                 }
9431                 current_switch->last_case = &statement->case_label;
9432         } else {
9433                 errorf(pos, "case label not within a switch statement");
9434         }
9435
9436         statement_t *const inner_stmt = parse_statement();
9437         statement->case_label.statement = inner_stmt;
9438         if (inner_stmt->kind == STATEMENT_DECLARATION) {
9439                 errorf(&inner_stmt->base.source_position, "declaration after case label");
9440         }
9441
9442         POP_PARENT;
9443         return statement;
9444 end_error:
9445         POP_PARENT;
9446         return create_invalid_statement();
9447 }
9448
9449 /**
9450  * Parse a default statement.
9451  */
9452 static statement_t *parse_default_statement(void)
9453 {
9454         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9455
9456         eat(T_default);
9457
9458         PUSH_PARENT(statement);
9459
9460         expect(':');
9461         if (current_switch != NULL) {
9462                 const case_label_statement_t *def_label = current_switch->default_label;
9463                 if (def_label != NULL) {
9464                         errorf(HERE, "multiple default labels in one switch (previous declared %P)",
9465                                &def_label->base.source_position);
9466                 } else {
9467                         current_switch->default_label = &statement->case_label;
9468
9469                         /* link all cases into the switch statement */
9470                         if (current_switch->last_case == NULL) {
9471                                 current_switch->first_case      = &statement->case_label;
9472                         } else {
9473                                 current_switch->last_case->next = &statement->case_label;
9474                         }
9475                         current_switch->last_case = &statement->case_label;
9476                 }
9477         } else {
9478                 errorf(&statement->base.source_position,
9479                         "'default' label not within a switch statement");
9480         }
9481
9482         statement_t *const inner_stmt = parse_statement();
9483         statement->case_label.statement = inner_stmt;
9484         if (inner_stmt->kind == STATEMENT_DECLARATION) {
9485                 errorf(&inner_stmt->base.source_position, "declaration after default label");
9486         }
9487
9488         POP_PARENT;
9489         return statement;
9490 end_error:
9491         POP_PARENT;
9492         return create_invalid_statement();
9493 }
9494
9495 /**
9496  * Parse a label statement.
9497  */
9498 static statement_t *parse_label_statement(void)
9499 {
9500         assert(token.type == T_IDENTIFIER);
9501         symbol_t *symbol = token.v.symbol;
9502         label_t  *label  = get_label(symbol);
9503
9504         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
9505         statement->label.label       = label;
9506
9507         next_token();
9508
9509         PUSH_PARENT(statement);
9510
9511         /* if statement is already set then the label is defined twice,
9512          * otherwise it was just mentioned in a goto/local label declaration so far
9513          */
9514         if (label->statement != NULL) {
9515                 errorf(HERE, "duplicate label '%Y' (declared %P)",
9516                        symbol, &label->base.source_position);
9517         } else {
9518                 label->base.source_position = token.source_position;
9519                 label->statement            = statement;
9520         }
9521
9522         eat(':');
9523
9524         if (token.type == '}') {
9525                 /* TODO only warn? */
9526                 if (warning.other && false) {
9527                         warningf(HERE, "label at end of compound statement");
9528                         statement->label.statement = create_empty_statement();
9529                 } else {
9530                         errorf(HERE, "label at end of compound statement");
9531                         statement->label.statement = create_invalid_statement();
9532                 }
9533         } else if (token.type == ';') {
9534                 /* Eat an empty statement here, to avoid the warning about an empty
9535                  * statement after a label.  label:; is commonly used to have a label
9536                  * before a closing brace. */
9537                 statement->label.statement = create_empty_statement();
9538                 next_token();
9539         } else {
9540                 statement_t *const inner_stmt = parse_statement();
9541                 statement->label.statement = inner_stmt;
9542                 if (inner_stmt->kind == STATEMENT_DECLARATION) {
9543                         errorf(&inner_stmt->base.source_position, "declaration after label");
9544                 }
9545         }
9546
9547         /* remember the labels in a list for later checking */
9548         *label_anchor = &statement->label;
9549         label_anchor  = &statement->label.next;
9550
9551         POP_PARENT;
9552         return statement;
9553 }
9554
9555 /**
9556  * Parse an if statement.
9557  */
9558 static statement_t *parse_if(void)
9559 {
9560         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
9561
9562         eat(T_if);
9563
9564         PUSH_PARENT(statement);
9565
9566         add_anchor_token('{');
9567
9568         expect('(');
9569         add_anchor_token(')');
9570         expression_t *const expr = parse_expression();
9571         statement->ifs.condition = expr;
9572         warn_reference_address_as_bool(expr);
9573         mark_vars_read(expr, NULL);
9574         rem_anchor_token(')');
9575         expect(')');
9576
9577 end_error:
9578         rem_anchor_token('{');
9579
9580         add_anchor_token(T_else);
9581         statement->ifs.true_statement = parse_statement();
9582         rem_anchor_token(T_else);
9583
9584         if (token.type == T_else) {
9585                 next_token();
9586                 statement->ifs.false_statement = parse_statement();
9587         }
9588
9589         POP_PARENT;
9590         return statement;
9591 }
9592
9593 /**
9594  * Check that all enums are handled in a switch.
9595  *
9596  * @param statement  the switch statement to check
9597  */
9598 static void check_enum_cases(const switch_statement_t *statement) {
9599         const type_t *type = skip_typeref(statement->expression->base.type);
9600         if (! is_type_enum(type))
9601                 return;
9602         const enum_type_t *enumt = &type->enumt;
9603
9604         /* if we have a default, no warnings */
9605         if (statement->default_label != NULL)
9606                 return;
9607
9608         /* FIXME: calculation of value should be done while parsing */
9609         /* TODO: quadratic algorithm here. Change to an n log n one */
9610         long            last_value = -1;
9611         const entity_t *entry      = enumt->enume->base.next;
9612         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
9613              entry = entry->base.next) {
9614                 const expression_t *expression = entry->enum_value.value;
9615                 long                value      = expression != NULL ? fold_constant(expression) : last_value + 1;
9616                 bool                found      = false;
9617                 for (const case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
9618                         if (l->expression == NULL)
9619                                 continue;
9620                         if (l->first_case <= value && value <= l->last_case) {
9621                                 found = true;
9622                                 break;
9623                         }
9624                 }
9625                 if (! found) {
9626                         warningf(&statement->base.source_position,
9627                                  "enumeration value '%Y' not handled in switch",
9628                                  entry->base.symbol);
9629                 }
9630                 last_value = value;
9631         }
9632 }
9633
9634 /**
9635  * Parse a switch statement.
9636  */
9637 static statement_t *parse_switch(void)
9638 {
9639         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
9640
9641         eat(T_switch);
9642
9643         PUSH_PARENT(statement);
9644
9645         expect('(');
9646         add_anchor_token(')');
9647         expression_t *const expr = parse_expression();
9648         mark_vars_read(expr, NULL);
9649         type_t       *      type = skip_typeref(expr->base.type);
9650         if (is_type_integer(type)) {
9651                 type = promote_integer(type);
9652                 if (warning.traditional) {
9653                         if (get_rank(type) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
9654                                 warningf(&expr->base.source_position,
9655                                         "'%T' switch expression not converted to '%T' in ISO C",
9656                                         type, type_int);
9657                         }
9658                 }
9659         } else if (is_type_valid(type)) {
9660                 errorf(&expr->base.source_position,
9661                        "switch quantity is not an integer, but '%T'", type);
9662                 type = type_error_type;
9663         }
9664         statement->switchs.expression = create_implicit_cast(expr, type);
9665         expect(')');
9666         rem_anchor_token(')');
9667
9668         switch_statement_t *rem = current_switch;
9669         current_switch          = &statement->switchs;
9670         statement->switchs.body = parse_statement();
9671         current_switch          = rem;
9672
9673         if (warning.switch_default &&
9674             statement->switchs.default_label == NULL) {
9675                 warningf(&statement->base.source_position, "switch has no default case");
9676         }
9677         if (warning.switch_enum)
9678                 check_enum_cases(&statement->switchs);
9679
9680         POP_PARENT;
9681         return statement;
9682 end_error:
9683         POP_PARENT;
9684         return create_invalid_statement();
9685 }
9686
9687 static statement_t *parse_loop_body(statement_t *const loop)
9688 {
9689         statement_t *const rem = current_loop;
9690         current_loop = loop;
9691
9692         statement_t *const body = parse_statement();
9693
9694         current_loop = rem;
9695         return body;
9696 }
9697
9698 /**
9699  * Parse a while statement.
9700  */
9701 static statement_t *parse_while(void)
9702 {
9703         statement_t *statement = allocate_statement_zero(STATEMENT_WHILE);
9704
9705         eat(T_while);
9706
9707         PUSH_PARENT(statement);
9708
9709         expect('(');
9710         add_anchor_token(')');
9711         expression_t *const cond = parse_expression();
9712         statement->whiles.condition = cond;
9713         warn_reference_address_as_bool(cond);
9714         mark_vars_read(cond, NULL);
9715         rem_anchor_token(')');
9716         expect(')');
9717
9718         statement->whiles.body = parse_loop_body(statement);
9719
9720         POP_PARENT;
9721         return statement;
9722 end_error:
9723         POP_PARENT;
9724         return create_invalid_statement();
9725 }
9726
9727 /**
9728  * Parse a do statement.
9729  */
9730 static statement_t *parse_do(void)
9731 {
9732         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
9733
9734         eat(T_do);
9735
9736         PUSH_PARENT(statement);
9737
9738         add_anchor_token(T_while);
9739         statement->do_while.body = parse_loop_body(statement);
9740         rem_anchor_token(T_while);
9741
9742         expect(T_while);
9743         expect('(');
9744         add_anchor_token(')');
9745         expression_t *const cond = parse_expression();
9746         statement->do_while.condition = cond;
9747         warn_reference_address_as_bool(cond);
9748         mark_vars_read(cond, NULL);
9749         rem_anchor_token(')');
9750         expect(')');
9751         expect(';');
9752
9753         POP_PARENT;
9754         return statement;
9755 end_error:
9756         POP_PARENT;
9757         return create_invalid_statement();
9758 }
9759
9760 /**
9761  * Parse a for statement.
9762  */
9763 static statement_t *parse_for(void)
9764 {
9765         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
9766
9767         eat(T_for);
9768
9769         PUSH_PARENT(statement);
9770
9771         size_t const top = environment_top();
9772         scope_push(&statement->fors.scope);
9773
9774         expect('(');
9775         add_anchor_token(')');
9776
9777         if (token.type != ';') {
9778                 if (is_declaration_specifier(&token, false)) {
9779                         parse_declaration(record_entity);
9780                 } else {
9781                         add_anchor_token(';');
9782                         expression_t *const init = parse_expression();
9783                         statement->fors.initialisation = init;
9784                         mark_vars_read(init, VAR_ANY);
9785                         if (warning.unused_value && !expression_has_effect(init)) {
9786                                 warningf(&init->base.source_position,
9787                                          "initialisation of 'for'-statement has no effect");
9788                         }
9789                         rem_anchor_token(';');
9790                         expect(';');
9791                 }
9792         } else {
9793                 expect(';');
9794         }
9795
9796         if (token.type != ';') {
9797                 add_anchor_token(';');
9798                 expression_t *const cond = parse_expression();
9799                 statement->fors.condition = cond;
9800                 warn_reference_address_as_bool(cond);
9801                 mark_vars_read(cond, NULL);
9802                 rem_anchor_token(';');
9803         }
9804         expect(';');
9805         if (token.type != ')') {
9806                 expression_t *const step = parse_expression();
9807                 statement->fors.step = step;
9808                 mark_vars_read(step, VAR_ANY);
9809                 if (warning.unused_value && !expression_has_effect(step)) {
9810                         warningf(&step->base.source_position,
9811                                  "step of 'for'-statement has no effect");
9812                 }
9813         }
9814         expect(')');
9815         rem_anchor_token(')');
9816         statement->fors.body = parse_loop_body(statement);
9817
9818         assert(current_scope == &statement->fors.scope);
9819         scope_pop();
9820         environment_pop_to(top);
9821
9822         POP_PARENT;
9823         return statement;
9824
9825 end_error:
9826         POP_PARENT;
9827         rem_anchor_token(')');
9828         assert(current_scope == &statement->fors.scope);
9829         scope_pop();
9830         environment_pop_to(top);
9831
9832         return create_invalid_statement();
9833 }
9834
9835 /**
9836  * Parse a goto statement.
9837  */
9838 static statement_t *parse_goto(void)
9839 {
9840         statement_t *statement = allocate_statement_zero(STATEMENT_GOTO);
9841         eat(T_goto);
9842
9843         if (GNU_MODE && token.type == '*') {
9844                 next_token();
9845                 expression_t *expression = parse_expression();
9846                 mark_vars_read(expression, NULL);
9847
9848                 /* Argh: although documentation says the expression must be of type void*,
9849                  * gcc accepts anything that can be casted into void* without error */
9850                 type_t *type = expression->base.type;
9851
9852                 if (type != type_error_type) {
9853                         if (!is_type_pointer(type) && !is_type_integer(type)) {
9854                                 errorf(&expression->base.source_position,
9855                                         "cannot convert to a pointer type");
9856                         } else if (warning.other && type != type_void_ptr) {
9857                                 warningf(&expression->base.source_position,
9858                                         "type of computed goto expression should be 'void*' not '%T'", type);
9859                         }
9860                         expression = create_implicit_cast(expression, type_void_ptr);
9861                 }
9862
9863                 statement->gotos.expression = expression;
9864         } else {
9865                 if (token.type != T_IDENTIFIER) {
9866                         if (GNU_MODE)
9867                                 parse_error_expected("while parsing goto", T_IDENTIFIER, '*', NULL);
9868                         else
9869                                 parse_error_expected("while parsing goto", T_IDENTIFIER, NULL);
9870                         eat_until_anchor();
9871                         goto end_error;
9872                 }
9873                 symbol_t *symbol = token.v.symbol;
9874                 next_token();
9875
9876                 statement->gotos.label = get_label(symbol);
9877         }
9878
9879         /* remember the goto's in a list for later checking */
9880         *goto_anchor = &statement->gotos;
9881         goto_anchor  = &statement->gotos.next;
9882
9883         expect(';');
9884
9885         return statement;
9886 end_error:
9887         return create_invalid_statement();
9888 }
9889
9890 /**
9891  * Parse a continue statement.
9892  */
9893 static statement_t *parse_continue(void)
9894 {
9895         if (current_loop == NULL) {
9896                 errorf(HERE, "continue statement not within loop");
9897         }
9898
9899         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
9900
9901         eat(T_continue);
9902         expect(';');
9903
9904 end_error:
9905         return statement;
9906 }
9907
9908 /**
9909  * Parse a break statement.
9910  */
9911 static statement_t *parse_break(void)
9912 {
9913         if (current_switch == NULL && current_loop == NULL) {
9914                 errorf(HERE, "break statement not within loop or switch");
9915         }
9916
9917         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
9918
9919         eat(T_break);
9920         expect(';');
9921
9922 end_error:
9923         return statement;
9924 }
9925
9926 /**
9927  * Parse a __leave statement.
9928  */
9929 static statement_t *parse_leave_statement(void)
9930 {
9931         if (current_try == NULL) {
9932                 errorf(HERE, "__leave statement not within __try");
9933         }
9934
9935         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
9936
9937         eat(T___leave);
9938         expect(';');
9939
9940 end_error:
9941         return statement;
9942 }
9943
9944 /**
9945  * Check if a given entity represents a local variable.
9946  */
9947 static bool is_local_variable(const entity_t *entity)
9948 {
9949         if (entity->kind != ENTITY_VARIABLE)
9950                 return false;
9951
9952         switch ((storage_class_tag_t) entity->declaration.storage_class) {
9953         case STORAGE_CLASS_AUTO:
9954         case STORAGE_CLASS_REGISTER: {
9955                 const type_t *type = skip_typeref(entity->declaration.type);
9956                 if (is_type_function(type)) {
9957                         return false;
9958                 } else {
9959                         return true;
9960                 }
9961         }
9962         default:
9963                 return false;
9964         }
9965 }
9966
9967 /**
9968  * Check if a given expression represents a local variable.
9969  */
9970 static bool expression_is_local_variable(const expression_t *expression)
9971 {
9972         if (expression->base.kind != EXPR_REFERENCE) {
9973                 return false;
9974         }
9975         const entity_t *entity = expression->reference.entity;
9976         return is_local_variable(entity);
9977 }
9978
9979 /**
9980  * Check if a given expression represents a local variable and
9981  * return its declaration then, else return NULL.
9982  */
9983 entity_t *expression_is_variable(const expression_t *expression)
9984 {
9985         if (expression->base.kind != EXPR_REFERENCE) {
9986                 return NULL;
9987         }
9988         entity_t *entity = expression->reference.entity;
9989         if (entity->kind != ENTITY_VARIABLE)
9990                 return NULL;
9991
9992         return entity;
9993 }
9994
9995 /**
9996  * Parse a return statement.
9997  */
9998 static statement_t *parse_return(void)
9999 {
10000         eat(T_return);
10001
10002         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
10003
10004         expression_t *return_value = NULL;
10005         if (token.type != ';') {
10006                 return_value = parse_expression();
10007                 mark_vars_read(return_value, NULL);
10008         }
10009
10010         const type_t *const func_type = skip_typeref(current_function->base.type);
10011         assert(is_type_function(func_type));
10012         type_t *const return_type = skip_typeref(func_type->function.return_type);
10013
10014         if (return_value != NULL) {
10015                 type_t *return_value_type = skip_typeref(return_value->base.type);
10016
10017                 if (is_type_atomic(return_type,        ATOMIC_TYPE_VOID) &&
10018                                 !is_type_atomic(return_value_type, ATOMIC_TYPE_VOID)) {
10019                         if (warning.other) {
10020                                 warningf(&statement->base.source_position,
10021                                                 "'return' with a value, in function returning void");
10022                         }
10023                         return_value = NULL;
10024                 } else {
10025                         assign_error_t error = semantic_assign(return_type, return_value);
10026                         report_assign_error(error, return_type, return_value, "'return'",
10027                                             &statement->base.source_position);
10028                         return_value = create_implicit_cast(return_value, return_type);
10029                 }
10030                 /* check for returning address of a local var */
10031                 if (warning.other && return_value != NULL
10032                                 && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
10033                         const expression_t *expression = return_value->unary.value;
10034                         if (expression_is_local_variable(expression)) {
10035                                 warningf(&statement->base.source_position,
10036                                          "function returns address of local variable");
10037                         }
10038                 }
10039         } else if (warning.other && !is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
10040                 warningf(&statement->base.source_position,
10041                                 "'return' without value, in function returning non-void");
10042         }
10043         statement->returns.value = return_value;
10044
10045         expect(';');
10046
10047 end_error:
10048         return statement;
10049 }
10050
10051 /**
10052  * Parse a declaration statement.
10053  */
10054 static statement_t *parse_declaration_statement(void)
10055 {
10056         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
10057
10058         entity_t *before = current_scope->last_entity;
10059         if (GNU_MODE)
10060                 parse_external_declaration();
10061         else
10062                 parse_declaration(record_entity);
10063
10064         if (before == NULL) {
10065                 statement->declaration.declarations_begin = current_scope->entities;
10066         } else {
10067                 statement->declaration.declarations_begin = before->base.next;
10068         }
10069         statement->declaration.declarations_end = current_scope->last_entity;
10070
10071         return statement;
10072 }
10073
10074 /**
10075  * Parse an expression statement, ie. expr ';'.
10076  */
10077 static statement_t *parse_expression_statement(void)
10078 {
10079         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10080
10081         expression_t *const expr         = parse_expression();
10082         statement->expression.expression = expr;
10083         mark_vars_read(expr, VAR_ANY);
10084
10085         expect(';');
10086
10087 end_error:
10088         return statement;
10089 }
10090
10091 /**
10092  * Parse a microsoft __try { } __finally { } or
10093  * __try{ } __except() { }
10094  */
10095 static statement_t *parse_ms_try_statment(void)
10096 {
10097         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
10098         eat(T___try);
10099
10100         PUSH_PARENT(statement);
10101
10102         ms_try_statement_t *rem = current_try;
10103         current_try = &statement->ms_try;
10104         statement->ms_try.try_statement = parse_compound_statement(false);
10105         current_try = rem;
10106
10107         POP_PARENT;
10108
10109         if (token.type == T___except) {
10110                 eat(T___except);
10111                 expect('(');
10112                 add_anchor_token(')');
10113                 expression_t *const expr = parse_expression();
10114                 mark_vars_read(expr, NULL);
10115                 type_t       *      type = skip_typeref(expr->base.type);
10116                 if (is_type_integer(type)) {
10117                         type = promote_integer(type);
10118                 } else if (is_type_valid(type)) {
10119                         errorf(&expr->base.source_position,
10120                                "__expect expression is not an integer, but '%T'", type);
10121                         type = type_error_type;
10122                 }
10123                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
10124                 rem_anchor_token(')');
10125                 expect(')');
10126                 statement->ms_try.final_statement = parse_compound_statement(false);
10127         } else if (token.type == T__finally) {
10128                 eat(T___finally);
10129                 statement->ms_try.final_statement = parse_compound_statement(false);
10130         } else {
10131                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
10132                 return create_invalid_statement();
10133         }
10134         return statement;
10135 end_error:
10136         return create_invalid_statement();
10137 }
10138
10139 static statement_t *parse_empty_statement(void)
10140 {
10141         if (warning.empty_statement) {
10142                 warningf(HERE, "statement is empty");
10143         }
10144         statement_t *const statement = create_empty_statement();
10145         eat(';');
10146         return statement;
10147 }
10148
10149 static statement_t *parse_local_label_declaration(void)
10150 {
10151         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
10152
10153         eat(T___label__);
10154
10155         entity_t *begin = NULL, *end = NULL;
10156
10157         while (true) {
10158                 if (token.type != T_IDENTIFIER) {
10159                         parse_error_expected("while parsing local label declaration",
10160                                 T_IDENTIFIER, NULL);
10161                         goto end_error;
10162                 }
10163                 symbol_t *symbol = token.v.symbol;
10164                 entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
10165                 if (entity != NULL && entity->base.parent_scope == current_scope) {
10166                         errorf(HERE, "multiple definitions of '__label__ %Y' (previous definition %P)",
10167                                symbol, &entity->base.source_position);
10168                 } else {
10169                         entity = allocate_entity_zero(ENTITY_LOCAL_LABEL);
10170
10171                         entity->base.parent_scope    = current_scope;
10172                         entity->base.namespc         = NAMESPACE_LABEL;
10173                         entity->base.source_position = token.source_position;
10174                         entity->base.symbol          = symbol;
10175
10176                         if (end != NULL)
10177                                 end->base.next = entity;
10178                         end = entity;
10179                         if (begin == NULL)
10180                                 begin = entity;
10181
10182                         environment_push(entity);
10183                 }
10184                 next_token();
10185
10186                 if (token.type != ',')
10187                         break;
10188                 next_token();
10189         }
10190         eat(';');
10191 end_error:
10192         statement->declaration.declarations_begin = begin;
10193         statement->declaration.declarations_end   = end;
10194         return statement;
10195 }
10196
10197 static void parse_namespace_definition(void)
10198 {
10199         eat(T_namespace);
10200
10201         entity_t *entity = NULL;
10202         symbol_t *symbol = NULL;
10203
10204         if (token.type == T_IDENTIFIER) {
10205                 symbol = token.v.symbol;
10206                 next_token();
10207
10208                 entity = get_entity(symbol, NAMESPACE_NORMAL);
10209                 if (entity != NULL && entity->kind != ENTITY_NAMESPACE
10210                                 && entity->base.parent_scope == current_scope) {
10211                         error_redefined_as_different_kind(&token.source_position,
10212                                                           entity, ENTITY_NAMESPACE);
10213                         entity = NULL;
10214                 }
10215         }
10216
10217         if (entity == NULL) {
10218                 entity                       = allocate_entity_zero(ENTITY_NAMESPACE);
10219                 entity->base.symbol          = symbol;
10220                 entity->base.source_position = token.source_position;
10221                 entity->base.namespc         = NAMESPACE_NORMAL;
10222                 entity->base.parent_scope    = current_scope;
10223         }
10224
10225         if (token.type == '=') {
10226                 /* TODO: parse namespace alias */
10227                 panic("namespace alias definition not supported yet");
10228         }
10229
10230         environment_push(entity);
10231         append_entity(current_scope, entity);
10232
10233         size_t const top = environment_top();
10234         scope_push(&entity->namespacee.members);
10235
10236         expect('{');
10237         parse_externals();
10238         expect('}');
10239
10240 end_error:
10241         assert(current_scope == &entity->namespacee.members);
10242         scope_pop();
10243         environment_pop_to(top);
10244 }
10245
10246 /**
10247  * Parse a statement.
10248  * There's also parse_statement() which additionally checks for
10249  * "statement has no effect" warnings
10250  */
10251 static statement_t *intern_parse_statement(void)
10252 {
10253         statement_t *statement = NULL;
10254
10255         /* declaration or statement */
10256         add_anchor_token(';');
10257         switch (token.type) {
10258         case T_IDENTIFIER: {
10259                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
10260                 if (la1_type == ':') {
10261                         statement = parse_label_statement();
10262                 } else if (is_typedef_symbol(token.v.symbol)) {
10263                         statement = parse_declaration_statement();
10264                 } else {
10265                         /* it's an identifier, the grammar says this must be an
10266                          * expression statement. However it is common that users mistype
10267                          * declaration types, so we guess a bit here to improve robustness
10268                          * for incorrect programs */
10269                         switch (la1_type) {
10270                         case '*':
10271                                 if (get_entity(token.v.symbol, NAMESPACE_NORMAL) != NULL)
10272                                         goto expression_statment;
10273                                 /* FALLTHROUGH */
10274
10275                         DECLARATION_START
10276                         case T_IDENTIFIER:
10277                                 statement = parse_declaration_statement();
10278                                 break;
10279
10280                         default:
10281 expression_statment:
10282                                 statement = parse_expression_statement();
10283                                 break;
10284                         }
10285                 }
10286                 break;
10287         }
10288
10289         case T___extension__:
10290                 /* This can be a prefix to a declaration or an expression statement.
10291                  * We simply eat it now and parse the rest with tail recursion. */
10292                 do {
10293                         next_token();
10294                 } while (token.type == T___extension__);
10295                 bool old_gcc_extension = in_gcc_extension;
10296                 in_gcc_extension       = true;
10297                 statement = parse_statement();
10298                 in_gcc_extension = old_gcc_extension;
10299                 break;
10300
10301         DECLARATION_START
10302                 statement = parse_declaration_statement();
10303                 break;
10304
10305         case T___label__:
10306                 statement = parse_local_label_declaration();
10307                 break;
10308
10309         case ';':         statement = parse_empty_statement();         break;
10310         case '{':         statement = parse_compound_statement(false); break;
10311         case T___leave:   statement = parse_leave_statement();         break;
10312         case T___try:     statement = parse_ms_try_statment();         break;
10313         case T_asm:       statement = parse_asm_statement();           break;
10314         case T_break:     statement = parse_break();                   break;
10315         case T_case:      statement = parse_case_statement();          break;
10316         case T_continue:  statement = parse_continue();                break;
10317         case T_default:   statement = parse_default_statement();       break;
10318         case T_do:        statement = parse_do();                      break;
10319         case T_for:       statement = parse_for();                     break;
10320         case T_goto:      statement = parse_goto();                    break;
10321         case T_if:        statement = parse_if();                      break;
10322         case T_return:    statement = parse_return();                  break;
10323         case T_switch:    statement = parse_switch();                  break;
10324         case T_while:     statement = parse_while();                   break;
10325
10326         EXPRESSION_START
10327                 statement = parse_expression_statement();
10328                 break;
10329
10330         default:
10331                 errorf(HERE, "unexpected token %K while parsing statement", &token);
10332                 statement = create_invalid_statement();
10333                 if (!at_anchor())
10334                         next_token();
10335                 break;
10336         }
10337         rem_anchor_token(';');
10338
10339         assert(statement != NULL
10340                         && statement->base.source_position.input_name != NULL);
10341
10342         return statement;
10343 }
10344
10345 /**
10346  * parse a statement and emits "statement has no effect" warning if needed
10347  * (This is really a wrapper around intern_parse_statement with check for 1
10348  *  single warning. It is needed, because for statement expressions we have
10349  *  to avoid the warning on the last statement)
10350  */
10351 static statement_t *parse_statement(void)
10352 {
10353         statement_t *statement = intern_parse_statement();
10354
10355         if (statement->kind == STATEMENT_EXPRESSION && warning.unused_value) {
10356                 expression_t *expression = statement->expression.expression;
10357                 if (!expression_has_effect(expression)) {
10358                         warningf(&expression->base.source_position,
10359                                         "statement has no effect");
10360                 }
10361         }
10362
10363         return statement;
10364 }
10365
10366 /**
10367  * Parse a compound statement.
10368  */
10369 static statement_t *parse_compound_statement(bool inside_expression_statement)
10370 {
10371         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
10372
10373         PUSH_PARENT(statement);
10374
10375         eat('{');
10376         add_anchor_token('}');
10377
10378         size_t const top = environment_top();
10379         scope_push(&statement->compound.scope);
10380
10381         statement_t **anchor            = &statement->compound.statements;
10382         bool          only_decls_so_far = true;
10383         while (token.type != '}') {
10384                 if (token.type == T_EOF) {
10385                         errorf(&statement->base.source_position,
10386                                "EOF while parsing compound statement");
10387                         break;
10388                 }
10389                 statement_t *sub_statement = intern_parse_statement();
10390                 if (is_invalid_statement(sub_statement)) {
10391                         /* an error occurred. if we are at an anchor, return */
10392                         if (at_anchor())
10393                                 goto end_error;
10394                         continue;
10395                 }
10396
10397                 if (warning.declaration_after_statement) {
10398                         if (sub_statement->kind != STATEMENT_DECLARATION) {
10399                                 only_decls_so_far = false;
10400                         } else if (!only_decls_so_far) {
10401                                 warningf(&sub_statement->base.source_position,
10402                                          "ISO C90 forbids mixed declarations and code");
10403                         }
10404                 }
10405
10406                 *anchor = sub_statement;
10407
10408                 while (sub_statement->base.next != NULL)
10409                         sub_statement = sub_statement->base.next;
10410
10411                 anchor = &sub_statement->base.next;
10412         }
10413         next_token();
10414
10415         /* look over all statements again to produce no effect warnings */
10416         if (warning.unused_value) {
10417                 statement_t *sub_statement = statement->compound.statements;
10418                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
10419                         if (sub_statement->kind != STATEMENT_EXPRESSION)
10420                                 continue;
10421                         /* don't emit a warning for the last expression in an expression
10422                          * statement as it has always an effect */
10423                         if (inside_expression_statement && sub_statement->base.next == NULL)
10424                                 continue;
10425
10426                         expression_t *expression = sub_statement->expression.expression;
10427                         if (!expression_has_effect(expression)) {
10428                                 warningf(&expression->base.source_position,
10429                                          "statement has no effect");
10430                         }
10431                 }
10432         }
10433
10434 end_error:
10435         rem_anchor_token('}');
10436         assert(current_scope == &statement->compound.scope);
10437         scope_pop();
10438         environment_pop_to(top);
10439
10440         POP_PARENT;
10441         return statement;
10442 }
10443
10444 /**
10445  * Check for unused global static functions and variables
10446  */
10447 static void check_unused_globals(void)
10448 {
10449         if (!warning.unused_function && !warning.unused_variable)
10450                 return;
10451
10452         for (const entity_t *entity = file_scope->entities; entity != NULL;
10453              entity = entity->base.next) {
10454                 if (!is_declaration(entity))
10455                         continue;
10456
10457                 const declaration_t *declaration = &entity->declaration;
10458                 if (declaration->used                  ||
10459                     declaration->modifiers & DM_UNUSED ||
10460                     declaration->modifiers & DM_USED   ||
10461                     declaration->storage_class != STORAGE_CLASS_STATIC)
10462                         continue;
10463
10464                 type_t *const type = declaration->type;
10465                 const char *s;
10466                 if (entity->kind == ENTITY_FUNCTION) {
10467                         /* inhibit warning for static inline functions */
10468                         if (entity->function.is_inline)
10469                                 continue;
10470
10471                         s = entity->function.statement != NULL ? "defined" : "declared";
10472                 } else {
10473                         s = "defined";
10474                 }
10475
10476                 warningf(&declaration->base.source_position, "'%#T' %s but not used",
10477                         type, declaration->base.symbol, s);
10478         }
10479 }
10480
10481 static void parse_global_asm(void)
10482 {
10483         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
10484
10485         eat(T_asm);
10486         expect('(');
10487
10488         statement->asms.asm_text = parse_string_literals();
10489         statement->base.next     = unit->global_asm;
10490         unit->global_asm         = statement;
10491
10492         expect(')');
10493         expect(';');
10494
10495 end_error:;
10496 }
10497
10498 static void parse_linkage_specification(void)
10499 {
10500         eat(T_extern);
10501         assert(token.type == T_STRING_LITERAL);
10502
10503         const char *linkage = parse_string_literals().begin;
10504
10505         linkage_kind_t old_linkage = current_linkage;
10506         linkage_kind_t new_linkage;
10507         if (strcmp(linkage, "C") == 0) {
10508                 new_linkage = LINKAGE_C;
10509         } else if (strcmp(linkage, "C++") == 0) {
10510                 new_linkage = LINKAGE_CXX;
10511         } else {
10512                 errorf(HERE, "linkage string \"%s\" not recognized", linkage);
10513                 new_linkage = LINKAGE_INVALID;
10514         }
10515         current_linkage = new_linkage;
10516
10517         if (token.type == '{') {
10518                 next_token();
10519                 parse_externals();
10520                 expect('}');
10521         } else {
10522                 parse_external();
10523         }
10524
10525 end_error:
10526         assert(current_linkage == new_linkage);
10527         current_linkage = old_linkage;
10528 }
10529
10530 static void parse_external(void)
10531 {
10532         switch (token.type) {
10533                 DECLARATION_START_NO_EXTERN
10534                 case T_IDENTIFIER:
10535                 case T___extension__:
10536                 case '(': /* for function declarations with implicit return type and
10537                                    * parenthesized declarator, i.e. (f)(void); */
10538                         parse_external_declaration();
10539                         return;
10540
10541                 case T_extern:
10542                         if (look_ahead(1)->type == T_STRING_LITERAL) {
10543                                 parse_linkage_specification();
10544                         } else {
10545                                 parse_external_declaration();
10546                         }
10547                         return;
10548
10549                 case T_asm:
10550                         parse_global_asm();
10551                         return;
10552
10553                 case T_namespace:
10554                         parse_namespace_definition();
10555                         return;
10556
10557                 case ';':
10558                         if (!strict_mode) {
10559                                 if (warning.other)
10560                                         warningf(HERE, "stray ';' outside of function");
10561                                 next_token();
10562                                 return;
10563                         }
10564                         /* FALLTHROUGH */
10565
10566                 default:
10567                         errorf(HERE, "stray %K outside of function", &token);
10568                         if (token.type == '(' || token.type == '{' || token.type == '[')
10569                                 eat_until_matching_token(token.type);
10570                         next_token();
10571                         return;
10572         }
10573 }
10574
10575 static void parse_externals(void)
10576 {
10577         add_anchor_token('}');
10578         add_anchor_token(T_EOF);
10579
10580 #ifndef NDEBUG
10581         unsigned char token_anchor_copy[T_LAST_TOKEN];
10582         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
10583 #endif
10584
10585         while (token.type != T_EOF && token.type != '}') {
10586 #ifndef NDEBUG
10587                 bool anchor_leak = false;
10588                 for (int i = 0; i != T_LAST_TOKEN; ++i) {
10589                         unsigned char count = token_anchor_set[i] - token_anchor_copy[i];
10590                         if (count != 0) {
10591                                 errorf(HERE, "Leaked anchor token %k %d times", i, count);
10592                                 anchor_leak = true;
10593                         }
10594                 }
10595                 if (in_gcc_extension) {
10596                         errorf(HERE, "Leaked __extension__");
10597                         anchor_leak = true;
10598                 }
10599
10600                 if (anchor_leak)
10601                         abort();
10602 #endif
10603
10604                 parse_external();
10605         }
10606
10607         rem_anchor_token(T_EOF);
10608         rem_anchor_token('}');
10609 }
10610
10611 /**
10612  * Parse a translation unit.
10613  */
10614 static void parse_translation_unit(void)
10615 {
10616         add_anchor_token(T_EOF);
10617
10618         while (true) {
10619                 parse_externals();
10620
10621                 if (token.type == T_EOF)
10622                         break;
10623
10624                 errorf(HERE, "stray %K outside of function", &token);
10625                 if (token.type == '(' || token.type == '{' || token.type == '[')
10626                         eat_until_matching_token(token.type);
10627                 next_token();
10628         }
10629 }
10630
10631 /**
10632  * Parse the input.
10633  *
10634  * @return  the translation unit or NULL if errors occurred.
10635  */
10636 void start_parsing(void)
10637 {
10638         environment_stack = NEW_ARR_F(stack_entry_t, 0);
10639         label_stack       = NEW_ARR_F(stack_entry_t, 0);
10640         diagnostic_count  = 0;
10641         error_count       = 0;
10642         warning_count     = 0;
10643
10644         type_set_output(stderr);
10645         ast_set_output(stderr);
10646
10647         assert(unit == NULL);
10648         unit = allocate_ast_zero(sizeof(unit[0]));
10649
10650         assert(file_scope == NULL);
10651         file_scope = &unit->scope;
10652
10653         assert(current_scope == NULL);
10654         scope_push(&unit->scope);
10655 }
10656
10657 translation_unit_t *finish_parsing(void)
10658 {
10659         /* do NOT use scope_pop() here, this will crash, will it by hand */
10660         assert(current_scope == &unit->scope);
10661         current_scope = NULL;
10662
10663         assert(file_scope == &unit->scope);
10664         check_unused_globals();
10665         file_scope = NULL;
10666
10667         DEL_ARR_F(environment_stack);
10668         DEL_ARR_F(label_stack);
10669
10670         translation_unit_t *result = unit;
10671         unit = NULL;
10672         return result;
10673 }
10674
10675 void parse(void)
10676 {
10677         lookahead_bufpos = 0;
10678         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
10679                 next_token();
10680         }
10681         current_linkage = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
10682         parse_translation_unit();
10683 }
10684
10685 /**
10686  * Initialize the parser.
10687  */
10688 void init_parser(void)
10689 {
10690         sym_anonymous = symbol_table_insert("<anonymous>");
10691
10692         if (c_mode & _MS) {
10693                 /* add predefined symbols for extended-decl-modifier */
10694                 sym_align      = symbol_table_insert("align");
10695                 sym_allocate   = symbol_table_insert("allocate");
10696                 sym_dllimport  = symbol_table_insert("dllimport");
10697                 sym_dllexport  = symbol_table_insert("dllexport");
10698                 sym_naked      = symbol_table_insert("naked");
10699                 sym_noinline   = symbol_table_insert("noinline");
10700                 sym_noreturn   = symbol_table_insert("noreturn");
10701                 sym_nothrow    = symbol_table_insert("nothrow");
10702                 sym_novtable   = symbol_table_insert("novtable");
10703                 sym_property   = symbol_table_insert("property");
10704                 sym_get        = symbol_table_insert("get");
10705                 sym_put        = symbol_table_insert("put");
10706                 sym_selectany  = symbol_table_insert("selectany");
10707                 sym_thread     = symbol_table_insert("thread");
10708                 sym_uuid       = symbol_table_insert("uuid");
10709                 sym_deprecated = symbol_table_insert("deprecated");
10710                 sym_restrict   = symbol_table_insert("restrict");
10711                 sym_noalias    = symbol_table_insert("noalias");
10712         }
10713         memset(token_anchor_set, 0, sizeof(token_anchor_set));
10714
10715         init_expression_parsers();
10716         obstack_init(&temp_obst);
10717
10718         symbol_t *const va_list_sym = symbol_table_insert("__builtin_va_list");
10719         type_valist = create_builtin_type(va_list_sym, type_void_ptr);
10720 }
10721
10722 /**
10723  * Terminate the parser.
10724  */
10725 void exit_parser(void)
10726 {
10727         obstack_free(&temp_obst, NULL);
10728 }